KR102424271B1 - Salt, acid generator, resist composition and method for producing resist pattern - Google Patents

Abstract

식 중, X^a 및 X^b는, 각각 독립적으로 산소 원자 또는 유황 원자를 나타내고, X¹은, 지환식 탄화수소기를 갖는 2 가의 기를 나타내고, 여기서 메틸렌기는, 산소 원자 또는 카르보닐기로 치환될 수 있고, 여기서 수소 원자는, 히드록시기 또는 불소 원자로 치환될 수 있고, *은 결합손을 나타낸다.A salt having a group represented by formula (a):

wherein, X ^a and X ^b each independently represent an oxygen atom or a sulfur atom, and X ¹ represents a divalent group having an alicyclic hydrocarbon group, wherein the methylene group may be substituted with an oxygen atom or a carbonyl group, wherein A hydrogen atom may be substituted with a hydroxyl group or a fluorine atom, and * represents a bond.

Description

Salt, acid generator, resist composition, and method for producing a resist pattern {SALT, ACID GENERATOR, RESIST COMPOSITION AND METHOD FOR PRODUCING RESIST PATTERN}

Cross-referencing of related applications

This application claims priority to Japanese Patent Application JP2014-170794 filed on August 25, 2014. The entire specification of Japanese patent application JP2014-170794 is hereby incorporated by reference.

background of the invention

1. Field of invention

The present invention relates to a salt, an acid generator, a resist composition, and a method for producing a resist pattern.

2. Prior art

A resist composition containing a salt represented by the following formula as an acid generator is described in the specification of JP2011-037837A.

Summary of the invention

The present invention provides the following inventions <1> to <11>.

<1> A salt having a group represented by formula (a).

wherein X ^a and X ^b each independently represent an oxygen atom or a sulfur atom,

X ¹ represents a divalent group having an alicyclic hydrocarbon group, the methylene group contained in the divalent group having the alicyclic hydrocarbon group may be substituted with an oxygen atom or a carbonyl group, and a hydrogen atom contained in the divalent group having the alicyclic hydrocarbon group may be substituted with a hydroxyl group or a fluorine atom,

* indicates a bond.

<2> The alicyclic hydrocarbon group is an adamantyl group, the methylene group contained in the adamantyl group may be substituted with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the adamantyl group may be substituted with a hydroxyl group <1 > according to salt.

<3> The salt according to <1> or <2>, which has a structure represented by formula (a1).

wherein X ^a , X ^b and * are defined in claim 1,

Ring W represents a C ₃ to C ₃₆ alicyclic hydrocarbon group, the methylene group contained in the alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxyl group, a C ₁ to C ₁₂ alkyl group, a C ₁ to C ₁₂ alkoxy group, a C ₃ to C ₁₂ alicyclic hydrocarbon group, a C ₆ to C ₁₀ aromatic hydrocarbon group, or a combination thereof. .

<4> The salt according to any one of <1> to <3>, containing an anion represented by the formula (a2).

wherein X ^a , X ^b and * are defined in claim 1,

Ring W represents a C ₃ to C ₃₆ alicyclic hydrocarbon group, the methylene group contained in the alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxyl group, a C ₁ to C ₁₂ alkyl group, a C ₁ to C ₁₂ alkoxy group, a C ₃ to C ₁₂ alicyclic hydrocarbon group, a C ₆ to C ₁₀ aromatic hydrocarbon group, or a combination thereof. ,

L ^b1 represents a C ₁ to C ₂₄ divalent saturated hydrocarbon group, the methylene group included in the saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group, and a hydrogen atom included in the saturated hydrocarbon group is a fluorine atom or a hydroxy group may be substituted, and

Q ¹ and Q ² each independently represent a fluorine atom or a C ₁ to C ₆ perfluoroalkyl group.

<5> The salt according to <3> or <4>,

Ring W is a ring represented by formula (a1-1), formula (a1-2) or formula (a1-3),

In each of the formulas (a1-1), (a1-2) and (a1-3), the methylene group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and the hydrogen atom is a hydroxyl group, C It may be substituted with a ₁ to C ₁₂ alkyl group, a C ₁ to C ₁₂ alkoxy group, a C ₃ to C ₁₂ alicyclic hydrocarbon group or a C ₆ to C ₁₀ aromatic hydrocarbon group.

<6> The salt according to <4>,

L ^b1 is *-CO-O-(CH ₂ ) _t -,

Here, t represents an integer of 0 to 6,

* represents a bond with -C(Q ¹ )(Q ² )-.

<7> The salt according to any one of <1> to <6>,

X ¹ is a divalent group represented by formula (X ^1-1 ), formula (X ^1-2 ), formula (X ^1-3 ), or formula (X ^1-4 ),

Here, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ represent a C ₅ to C ₁₂ alicyclic hydrocarbon group, and the methylene group included in the alicyclic hydrocarbon group is substituted with an oxygen atom or a carbonyl group, may be present, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxyl group or a fluorine atom,

* represents a bond with X ^a and X ^b .

<8> An acid generator containing the salt according to any one of <1> to <7>.

<9> A resist composition comprising the acid generator according to <8> and a resin having an acid labile group.

<10> The resist composition according to <9>, further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.

<11> A method for producing a resist pattern comprising steps (1) to (5):

(1) a step of applying the resist composition according to <9> or <10> on a substrate;

(2) drying the applied composition to form a composition layer;

(3) a step of exposing the composition layer;

(4) heating the exposed composition layer; and

(5) A step of developing the heated composition layer.

Description of preferred embodiments

"(meth)acrylic monomer" means a monomer having a structure of "CH ₂ =CH-CO-" or "CH ₂ =C(CH ₃ )-CO-", and similarly "(meth)acrylate" and "(meth)acrylic acid" means "acrylate or methacrylate" and "acrylic acid or methacrylic acid", respectively. Here, the chain structure groups include a group having a straight-chain structure and a group having a branched structure. The indefinite articles “a” and “an” have the same meaning as “one or more”.

In the present specification, the term "solid content" means components other than the solvent from the resist composition.

< Salt (a) >

The salt of the present invention is a salt having a group represented by formula (a), and is sometimes referred to as “salt (a)”. The salt (a) is a salt that generates an acid by radiation such as light.

Here, X ^a and X ^b independently represent an oxygen atom or a sulfur atom,

X ¹ represents a divalent group having an alicyclic hydrocarbon group, the methylene group contained in the divalent group having the alicyclic hydrocarbon group may be substituted with an oxygen atom or a carbonyl group, and a hydrogen atom contained in the divalent group having the alicyclic hydrocarbon group may be substituted with a hydroxyl group or a fluorine atom,

* indicates a bond.

X ^a and X ^b are preferably the same atoms independently of each other, and more preferably both are oxygen atoms.

The divalent group represented by X ¹ may have two or more alicyclic hydrocarbon groups, preferably one or two.

The alicyclic hydrocarbon group is preferably an adamantyl group, the methylene group contained in the adamantyl group may be substituted with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the adamantyl group may be substituted with a hydroxyl group.

Examples of the divalent group represented by X ¹ include a divalent saturated hydrocarbon group having an alicyclic hydrocarbon group, specifically a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a monocyclic or polycyclic alicyclic saturated hydrocarbon group. and a group combining an alkanediyl group, and a group combining at least three of alkanediyl groups and monocyclic or polycyclic alicyclic saturated hydrocarbon groups.

In the divalent group represented by X ¹ , The alicyclic saturated hydrocarbon group may be monovalent or divalent, preferably monovalent, and the methylene group contained in the alicyclic saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group, and hydrogen contained in the alicyclic saturated hydrocarbon group The atom may be substituted with a hydroxyl group or a fluorine atom.

Specific examples of the monovalent alicyclic saturated hydrocarbon group include C ₅ to C ₁₀ cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group and a cyclooctyl group, and a C ₈ to C ₁₂ polyalkyl group such as an adamantyl group or a norbornyl group. A cyclic monovalent alicyclic hydrocarbon group, and such cycloalkyl and monovalent alicyclic hydrocarbon groups in which a methylene group is substituted with an oxygen atom or a carbonyl group and a hydrogen atom is substituted with a hydroxyl group or a fluorine atom are included.

Specific examples of the divalent alicyclic saturated hydrocarbon group include monocyclic divalent alicyclic hydrocarbon groups, for example, a cycloalkanediyl group, preferably a cyclobutane-1,3-diyl group, cyclopentane-1, a C ₄ to C ₈ cycloalkanediyl group such as a 3-diyl group, a cyclohexane-1,4-diyl group, and a cyclooctane-1,5-diyl group; and,

Polycyclic divalent alicyclic hydrocarbon groups, preferably norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane- and C ₅ to C ₁₂ divalent alicyclic hydrocarbon groups such as 2,6-diyl group.

The alicyclic hydrocarbon group is preferably a C ₅ to C ₁₀ cycloalkyl group in which a methylene group is substituted with an oxygen atom or a carbonyl group and a hydrogen atom is substituted with a hydroxyl group or a fluorine atom, or a C ₈ to C ₁₂ polycyclic monovalent alicyclic ring Formula hydrocarbon groups, and more preferably an adamantyl group, the methylene group included in the adamantyl group may be substituted with an oxygen atom or a carbonyl group, and a hydrogen atom included in the adamantyl group is substituted with a hydroxyl group there may be When the divalent group represented by X ¹ has two or more alicyclic hydrocarbon groups, the two alicyclic hydrocarbon groups may form one spiro ring together. An example of such a spiro ring includes a ring composed of one adamantane ring and one C ₅ to C ₁₀ cycloalkyl group, and the methylene group included in the C ₅ to C ₁₀ cycloalkyl group is substituted with an oxygen atom or a carbonyl group may be, and the hydrogen atom contained in the said adamantyl group may be substituted by the hydroxyl group or the fluorine atom.

For X ¹ , examples of the alkanediyl group include a chain alkanediyl group, preferably a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. a C ₁ to C ₁₂ chain alkanediyl group, such as a diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, or an octane-1,8-diyl group;

Branched alkanediyl group, preferably ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4 -Diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, such as , a C ₂ to C ₁₂ chain alkanediyl group.

Among the said divalent group, the C1 _{- C12} alkanediyl group which has the said alicyclic hydrocarbon group is preferable, and the C1 _- C6 _alkanediyl group which has an alicyclic hydrocarbon group is more preferable.

Specifically, the divalent group represented by X ¹ preferably has an alkanediyl group in which one to three methylene groups are substituted with an oxygen atom or a carbonyl group, more preferably one or two methylene groups with an oxygen atom or a carbonyl group It has a substituted alkanediyl group. That is, the divalent group represented by X ¹ preferably has an oxycarbonyl group or a carbonyloxy group, and more preferably has one or two oxycarbonyl groups or a carbonyloxy group.

The divalent group of X ¹ is preferably a divalent saturated hydrocarbon group having a C ₅ to C ₁₂ alicyclic hydrocarbon group, more preferably a C ₅ to C ₁₂ alicyclic hydrocarbon group, an oxycarbonyl group or a carbonyloxy group. a divalent saturated hydrocarbon group, more preferably a divalent alkanediyl group having a C ₅ to C ₁₂ alicyclic hydrocarbon group, more preferably a C ₅ to C ₁₂ alicyclic hydrocarbon group, an oxycarbonyl group or a carbonyloxy group It is a divalent alkanediyl group having.

In particular, the divalent group of X ¹ is preferably a divalent group represented by a formula (X ^1-1 ), a formula (X ^1-2 ), a formula (X ^1-3 ), or a formula (X ^1-4 ), , More preferably, it is a divalent group represented by a formula (X ^1-1 ) or a formula (X ^1-4 ), More preferably, it is a divalent group represented by a formula (X ^1-4 ).

[During the ceremony,

Here, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ represent a C ₅ to C ₁₂ alicyclic hydrocarbon group, and the methylene group included in the alicyclic hydrocarbon group may be substituted with an oxygen atom or a carbonyl group. and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxyl group or a fluorine atom,

* represents a bond with X ^a or X ^b .

The salt (a) preferably has a group represented by the formula (a1).

Here, X ^a , X ^b , X ¹ and * represent the same meaning as above, and

Ring W represents a C ₃ to C ₃₆ alicyclic hydrocarbon group, the methylene group contained in the alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxyl group, a C ₁ to C ₁₂ alkyl group, a C ₁ to C ₁₂ alkoxy group, a C ₃ to C ₁₂ alicyclic hydrocarbon group, a C ₆ to C ₁₀ aromatic hydrocarbon group, or a combination thereof. .

Examples of the alicyclic hydrocarbon group for ring W include rings represented by formulas (a1-1) to (a1-11).

In the formulas (a1-1) to (a1-11), the methylene group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and the hydrogen atom is a hydroxy group, a C ₁ to C ₁₂ alkyl group, C ₁ to It may be substituted with a C ₁₂ alkoxy group, a C ₃ to C ₁₂ alicyclic hydrocarbon group, or a C ₆ to C ₁₀ aromatic hydrocarbon group.

As a substituent in formulas (a1-1) to (a1-11), examples of a C ₁ to C ₁₂ alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group and a dodecyl group.

As a substituent in the formulas (a1-1) to (a1-11), examples of the C ₁ to C ₁₂ alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, and dodecyloxy group.

As the substituent in formulas (a1-1) to (a1-11), examples of the C ₃ to C ₁₂ alicyclic group include the following groups represented by formulas (a1-1) to (a1-11) do. * is a bond with a ring.

As the substituent, examples of the C ₆ to C ₁₀ aromatic hydrocarbon group include a phenyl group and a naphthyl group.

Ring W is preferably a C ₃ to C ₁₈ alicyclic hydrocarbon group, more preferably a ring represented by formula (a1-1), formula (a1-2), or formula (a1-3).

Any carbon atom in the formulas (a1-1) to (a1-11) may be bonded to X ^a and X ^b .

Salt (a), Preferably it is a salt whose cation is an organic cation, Preferably it is a salt of the anion which has group and cation represented by Formula (a), More preferably, it is represented by Formula (a), It is a salt of an anion having a group and an organic cation.

The salt (a) preferably has an anion represented by the formula (a2).

Here, X ^a , X ^b , X ¹ and W represent the same meaning as above,

L ^b1 represents a C ₁ to C ₂₄ divalent saturated hydrocarbon group, the methylene group included in the saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group, and a hydrogen atom included in the saturated hydrocarbon group is a fluorine atom or a hydroxy group may be substituted,

Q ¹ and Q ² each independently represent a fluorine atom or a C ₁ to C ₆ perfluoroalkyl group.

Examples of the perfluoroalkyl group of Q ¹ and Q ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, and a perfluorosec-butyl group. , a perfluoro tert-butyl group, a perfluoropentyl group and a perfluorohexyl group.

Among these, Q ¹ and Q ² each independently preferably represent a trifluoromethyl group or a fluorine atom, and more preferably both Q ¹ and Q ² represent a fluorine atom.

Examples of the divalent saturated hydrocarbon group of L ^b1 include an alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations of two or more of these groups.

Specific examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, Heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1 ,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1 chain alkanediyl groups, such as ,17-diyl groups;

Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group;

Monocyclic divalent alicyclic saturated, such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group hydrocarbon group; and

polycyclic 2 such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group It contains a valent alicyclic saturated hydrocarbon group.

Examples of the divalent saturated hydrocarbon group in which the methylene group of L ^b1 is substituted with an oxygen atom or a carbonyl group include groups represented by formulas (b1-1) to (b1-3), and * is a bond with -W indicates

Here, L ^b2 represents a single bond or a C ₁ to C ₂₂ divalent saturated hydrocarbon group, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom,

L ^b3 represents a single bond or a C ₁ to C ₂₂ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and a methylene group contained in the saturated hydrocarbon group is an oxygen atom Or may be substituted with a carbonyl group,

However, the total number of carbon atoms included in the groups of L ^b2 and L ^b3 is 22 or less,

L ^b4 represents a single bond or a C ₁ to C ₂₂ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom,

L ^b5 represents a single bond or a C ₁ to C ₂₂ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and a methylene group contained in the saturated hydrocarbon group is an oxygen atom Or may be substituted with a carbonyl group,

However, the total number of carbon atoms included in the groups of L ^b4 and L ^b5 is 22 or less,

L ^b6 represents a single bond or a C ₁ to C ₂₃ divalent saturated hydrocarbon group, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group;

L ^b7 represents a single bond or a C ₁ to C ₂₃ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and a methylene group contained in the saturated hydrocarbon group is an oxygen atom Or may be substituted with a carbonyl group,

However, the total number of carbon atoms contained in the groups of L ^b6 and L ^b7 is 23 or less.

In the formulas (b1-1) to (b1-3), when the methylene group contained in the saturated hydrocarbon group is substituted with an oxygen atom or a carbonyl group, the number of carbon atoms in the saturated hydrocarbon group corresponds to the number of carbon atoms before substitution.

With respect to formulas (b1-1) to (b1-3), examples of the divalent saturated hydrocarbon group include an alkanediyl group and a monocyclic or polycyclic divalent saturated hydrocarbon group, and combinations of two or more of these groups include that

Specific examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. , heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane- 1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane- chain alkanediyl groups, such as 1,17-diyl groups;

Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group;

Monocyclic divalent alicyclic saturated, such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group hydrocarbon group; and

polycyclic 2 such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group It contains a valent alicyclic saturated hydrocarbon group.

L ^b2 is preferably a single bond.

L ^b3 is preferably a C ₁ to C ₄ divalent saturated hydrocarbon group.

L ^b4 is preferably a C ₁ to C ₈ divalent saturated hydrocarbon group, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b5 is preferably a single bond or a divalent saturated hydrocarbon group of C ₁ to C ₈ .

L ^b6 is preferably a single bond or a divalent saturated hydrocarbon group of C ₁ to C ₄ , and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b7 is preferably a single bond or a divalent saturated hydrocarbon group of C ₁ to C ₁₈ , the hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group, and methylene contained in the saturated hydrocarbon group The group may be substituted with an oxygen atom or a carbonyl group.

L ^b1 is preferably a group represented by formula (b1-1) or (b1-3), and more preferably a group represented by formula (b1-1).

Examples of the divalent group represented by formula (b1-1) include groups represented by formulas (b1-4) to (b1-8).

Here, L ^b8 represents a single bond or a C ₁ to C ₂₂ divalent saturated hydrocarbon group, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group,

L ^b9 represents a C ₁ to C ₂₀ divalent saturated hydrocarbon group,

L ^b10 represents a single bond or a C ₁ to C ₁₉ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group;

However, the total number of carbon atoms included in the groups of L ^b9 and L ^b10 is 20 or less,

L ^b11 represents a C ₁ to C ₂₁ divalent saturated hydrocarbon group,

L ^b12 represents a single bond or a C ₁ to C ₂₀ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group;

However, the total number of carbon atoms included in the groups of L ^b11 and L ^b12 is 21 or less,

L ^b13 represents a divalent saturated hydrocarbon group of C ₁ to C ₁₉ ,

L ^b14 represents a single bond or a divalent saturated hydrocarbon group of C ₁ to C ₁₈ ,

L ^b15 represents a single bond or a C ₁ to C ₁₈ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group;

provided that the total number of carbon atoms contained in the groups of L ^b13 , L ^b14 and L ^b15 is 19 or less,

L ^b16 represents a C ₁ to C ₁₈ divalent saturated hydrocarbon group,

L ^b17 represents a C ₁ to C ₁₈ divalent saturated hydrocarbon group.

L ^b18 represents a single bond or a C ₁ to C ₁₇ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxyl group;

However, the total number of carbon atoms contained in the groups of L ^b16 , L ^b17 and L ^b18 is 19 or less.

L ^b8 is preferably a C ₁ to C ₄ divalent saturated hydrocarbon group.

L ^b9 is preferably a C ₁ to C ₈ divalent saturated hydrocarbon group.

L ^b10 is preferably a single bond or a C ₁ to C ₁₉ divalent saturated hydrocarbon group, and more preferably a single bond or a C ₁ to C ₈ divalent saturated hydrocarbon group.

L ^b11 is preferably a C ₁ to C ₈ divalent saturated hydrocarbon group.

L ^b12 is preferably a single bond or a divalent saturated hydrocarbon group of C ₁ to C ₈ .

L ^b13 is preferably a C ₁ to C ₁₂ divalent saturated hydrocarbon group.

L ^b14 is preferably a single bond or a divalent saturated hydrocarbon group of C ₁ to C ₆ .

L ^b15 is preferably a single bond or a C ₁ to C ₁₈ divalent saturated hydrocarbon group, and more preferably a single bond or a C ₁ to C ₈ divalent saturated hydrocarbon group.

L ^b16 preferably represents a C ₁ to C ₁₂ divalent saturated hydrocarbon group.

L ^b17 preferably represents a C ₁ to C ₆ divalent saturated hydrocarbon group.

L ^b18 is preferably a single bond or a C ₁ to C ₁₇ divalent saturated hydrocarbon group, and more preferably a single bond or a C ₁ to C ₄ divalent saturated hydrocarbon group.

Examples of the divalent group represented by formula (b1-3) include groups represented by formulas (b1-9) to (b1-11).

Here, L ^b19 represents a single bond or a C ₁ to C ₂₃ divalent saturated hydrocarbon group, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom.

L ^b20 represents a single bond or a C ₁ to C ₂₃ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an acyloxy group, and the methylene group contained in the acyloxy group is , an oxygen atom or a carbonyl group may be substituted, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxyl group,

provided that the total number of carbon atoms in the groups of L ^b19 and L ^b20 is 23 or less,

L ^b21 represents a single bond or a C ₁ to C ₂₁ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom;

L ^b22 represents a single bond or a C ₁ to C ₂₁ divalent saturated hydrocarbon group,

L ^b23 represents a single bond or a C ₁ to C ₂₁ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an acyloxy group, and the methylene group contained in the acyloxy group is , an oxygen atom or a carbonyl group may be substituted, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxyl group,

provided that the total number of carbon atoms included in the groups of L ^b21 , L ^b22 and L ^b23 is 21 or less,

L ^b24 represents a single bond or a C ₁ to C ₂₀ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom,

L ^b25 represents a single bond or a C ₁ to C ₂₁ divalent saturated hydrocarbon group,

L ^b26 represents a single bond or a C ₁ to C ₂₀ divalent saturated hydrocarbon group, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an acyloxy group, and the methylene group contained in the acyloxy group is , an oxygen atom or a carbonyl group may be substituted, and the hydrogen atom contained in the acyloxy group may be substituted with a hydroxyl group,

However, the total number of carbon atoms contained in the groups of L ^b24 , L ^b25 and L ^b26 is 21 or less.

In the formulas (b1-9) to (b1-11), when a hydrogen atom contained in the saturated hydrocarbon group is substituted with an acyloxy group, the number of carbon atoms in the saturated hydrocarbon group is added to the carbon number of the saturated hydrocarbon group, and carbon atoms, CO and O corresponds to the number of

For formulas (b1-9) to (b1-11), examples of the divalent saturated hydrocarbon group include an alkanediyl group and a monocyclic or polycyclic divalent saturated hydrocarbon group, and combinations of two or more of these groups include that

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

Examples of the acyloxy group having a substituent include an oxoadamantylcarbonyloxy group, a hydroxyadamantylcarbonyloxy group, an oxocyclohexylcarbonyloxy group, and a hydroxycyclohexylcarbonyloxy group.

Examples of the group represented by formula (b1-4) include the following.

Examples of the group represented by formula (b1-5) include the following.

Examples of the group represented by the formula (b1-6) include the following.

Examples of the group represented by the formula (b1-7) include the following.

Examples of the group represented by formula (b1-8) include the following.

Examples of the group represented by the formula (b1-2) include the following.

Examples of the group represented by the formula (b1-9) include the following.

Examples of the group represented by formula (b1-10) include the following.

Examples of the group represented by the formula (b1-11) include the following.

Examples of the anion represented by formula (a2) include the following.

The cation of the salt (a) is preferably an organic cation. Examples of organic cations include organic onium cations such as organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, an organic sulfonium cation and an organic iodonium cation are preferable, and an aryl sulfonium cation is more preferable. Among these, cations represented by formulas (b2-1) to (b2-4) are preferable, wherein the cations are referred to as "cation X" (X represents the formula number of the cation) there is

Here, R ^b4 , R ^b5 and R ^b6 each independently represent a C ₁ to C ₃₀ aliphatic hydrocarbon group, a C ₃ to C ₃₆ alicyclic hydrocarbon group or a C ₆ to C ₃₆ aromatic hydrocarbon group, and the aliphatic hydrocarbon The hydrogen atom contained in the group may be substituted with a hydroxyl group, a C ₁ to C ₁₂ alkoxy group, a C ₃ to C ₁₂ alicyclic hydrocarbon group or a C ₆ to C ₁₈ aromatic hydrocarbon group, and is included in the alicyclic hydrocarbon group The hydrogen atom may be substituted with a halogen atom, a C ₁ to C ₁₈ aliphatic hydrocarbon group, a C ₂ to C ₄ acyl group or a glycidyloxy group, and the hydrogen atom contained in the aromatic hydrocarbon group is a halogen atom or a hydroxyl group. Alternatively, it may be substituted with a C ₁ to C ₁₂ alkoxy group, or R ^b4 and R ^b5 may be bonded together with a sulfur atom to which they are bonded to form a ring containing sulfur, and the methylene group contained in the ring is oxygen may be substituted with an atom, a sulfur atom or a carbonyl group,

In each case, R ^b7 and R ^b8 each independently represent a hydroxyl group, a C ₁ to C ₁₂ aliphatic hydrocarbon group or a C ₁ to C ₁₂ alkoxy group.

m2 and n2 each independently represent the integer of 0-5.

R ^b9 and R ^b10 each independently represent a C ₁ to C ₃₆ aliphatic hydrocarbon group or a C ₃ to C ₃₆ alicyclic hydrocarbon group, or R ^b9 and R ^b10 are bonded together with a sulfur atom bonded thereto A ring containing sulfur may be formed, and the methylene group contained in the ring may be substituted with an oxygen atom, a sulfur atom, or a carbonyl group,

R ^b11 represents a hydrogen atom, a C ₁ to C ₃₆ aliphatic hydrocarbon group, a C ₃ to C ₃₆ alicyclic hydrocarbon group, or a C ₆ to C ₁₈ aromatic hydrocarbon group,

R ^b12 represents a C ₁ to C ₁₂ aliphatic hydrocarbon group, a C ₃ to C ₁₈ alicyclic hydrocarbon group or a C ₆ to C ₁₈ aromatic hydrocarbon group, and a hydrogen atom included in the aliphatic hydrocarbon is C ₆ to C ₁₈ may be substituted with an aromatic hydrocarbon group, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a C ₁ to C ₁₂ alkoxy group or a C ₁ to C ₁₂ alkylcarbonyloxy group.

R ^b11 and R ^b12 may be bonded together with -CH-CO- to which they are bonded to form a ring, and the methylene group contained in the ring may be substituted with an oxygen atom, a sulfur atom or a carbonyl group,

R ^b13 , R ^b14 , R ^b15 , R ^b16 , R ^b17 , and R ^b18 in each case independently represent a hydroxy group, a C ₁ to C ₁₂ aliphatic hydrocarbon group or a C ₁ to C ₁₂ alkoxy group,

L ^b31 represents -S- or -O-,

o2, p2, s2, and t2 each independently represent an integer of 0 to 5;

q2 and r2 each independently represent an integer of 0 to 4, and

u2 represents an integer of 0 or 1.

Examples of the aliphatic hydrocarbon group are preferably methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n- octyl group and 2-ethylhexyl group. Among them, R ^b9 The aliphatic hydrocarbon group of to R ^b12 is preferably a C ₁ to C ₁₂ aliphatic hydrocarbon group.

Examples of the alicyclic hydrocarbon group include monocyclic groups such as a cycloalkyl group, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group; and decahydronaphthyl group, adamantyl group, norbornyl group, and polycyclic hydrocarbon groups such as the following groups.

Among them, R ^b9 The alicyclic hydrocarbon group of to R ^b12 is preferably a C ₃ to C ₁₈ alicyclic group, and more preferably a C ₄ to C ₁₂ alicyclic hydrocarbon group.

Examples of the alicyclic hydrocarbon group in which a hydrogen atom may be substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-alkyladamantan-2-yl group, a methylnorbornyl group, and an isobornyl group. In the alicyclic hydrocarbon group in which a hydrogen atom may be substituted with an aliphatic hydrocarbon group, the total number of carbon atoms in the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

Examples of the aromatic hydrocarbon group are preferably a phenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a p-cyclohexylphenyl group, a p-adamantylphenyl group, and an aryl group such as a biphenylyl group, a naphthyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.

When the aromatic hydrocarbon group includes an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, a C ₁ to C ₁₈ aliphatic hydrocarbon group or a C ₃ to C ₁₈ alicyclic hydrocarbon group is preferable.

Examples of the aromatic hydrocarbon group in which a hydrogen atom may be substituted with an alkoxy group include a p-methoxyphenyl group.

Examples of the aliphatic hydrocarbon group in which a hydrogen atom may be substituted with an aromatic hydrocarbon group include an aralkyl group, such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group and a dodecyloxy group.

Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

Examples of the alkylcarbonyloxy group are methylcarbonyloxy group, ethylcarbonyloxy group, n-propylcarbonyloxy group, isopropylcarbonyloxy group, n-butylcarbonyloxy group, sec-butylcarbonyloxy group group, tert-butylcarbonyloxy group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group and 2-ethylhexylcarbonyloxy group.

The ring including the sulfur atom formed by R ^b4 and R ^b5 may be a monocyclic or polycyclic ring, an aromatic or non-aromatic ring, and may be a saturated or unsaturated ring. This ring is preferably a ring having 3 to 18 carbon atoms, more preferably a ring having 4 to 13 carbon atoms. Examples of the ring containing a sulfur atom include a 3- to 12-membered ring, preferably a 3- to 7-membered ring, and examples thereof include the following ring.

Examples of the ring formed by R ^b9 and R ^b10 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples of the ring include a thiolan-1-ium ring (tetrahydrothiophenium ring), a thiane-1-ium ring, and a 1,4-oxathian-4-ium ring.

R ^b11 And examples of the ring formed by R ^b12 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples of the ring include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cations represented by the formulas (b2-1) to (b2-4), the cation represented by the formula (b2-1) is preferable.

Specific examples of the cation of formula (b2-1) include the following.

Specific examples of the cation of formula (b2-2) include the following.

Specific examples of the cation of formula (b2-3) include the following.

Salt (a) includes salts having any combination of anion and cation described above.

Specific examples of salt (a) include the following.

<Method for preparing salt (a)>

(1) X ¹ is a divalent group represented by formula (X ^1-1 ), has an anion represented by formula (a2), and an organic cation (Z ⁺ ), which is represented by formula (I1), A method for preparing salt (a), sometimes referred to as “salt (I1)”, is described below.

Salt (I1) can be produced by reacting a salt represented by formula (I1-a) with a reaction product of a compound represented by formula (I1-b) and carbonyldiimidazole in a solvent.

Here, X ^a , X ^b , L ¹ , Q ¹ , Q ² , rings W, Z ⁺ and R ¹ have the same meanings as above.

Preferred examples of the solvent include chloroform and acetonitrile.

Preferred examples of the compound represented by the formula (I1-b) include those represented by the following formula, which are readily available in the market.

The salt represented by the formula (I1-a) can be produced by reacting the salt represented by the formula (I1-c) and the compound represented by the formula (I1-d) in a solvent under an acid catalyst.

Here, X ^a , X ^b , L ¹ , Q ¹ , Q ² , Z ⁺ and ring W have the same meanings as above.

Preferred examples of the acid catalyst include p-toluenesulfonic acid.

Preferred examples of the solvent include chloroform, acetonitrile, and dimethylformamide.

The salt represented by Formula (I1-c) can be manufactured according to the method of Unexamined-Japanese-Patent No. 2007-224008, and Unexamined-Japanese-Patent No. 2012-224611. Examples of such salts include those indicated below.

Examples of the compound represented by the formula (I1-d) include those represented by the following formula, which are readily available in the market.

(2) X ¹ is a divalent group represented by formula (X ^1-4 ), has an anion represented by formula (a2), and an organic cation (Z ⁺ ), this salt is represented by formula (I2) A method for preparing salt (a), sometimes referred to as “salt (I2)”, is described below.

Salt (I2) is a solvent obtained by reacting a salt represented by formula (I2-a) with a compound represented by formula (I2-b) and a compound represented by formula (I2-b′) with carbonyldiimidazole. It can be manufactured by making it react in

Here, X ^a , X ^b , L ¹ , Q ¹ , Q ² , Z ⁺ , rings W, R ⁵ and R ⁶ have the same meanings as above.

Preferred examples of the solvent include chloroform and acetonitrile.

Preferred examples of the compound represented by the formula (I2-b) and the compound represented by the formula (I2-b') include those represented by the following formula, which are readily available in the market.

The salt represented by the formula (I2-a) can be produced by reacting the salt represented by the formula (I2-c) and the compound represented by the formula (I2-d) in a solvent under an acid catalyst.

Here, X ^a , X ^b , L ¹ , Q ¹ , Q ² , Z ⁺ , ring W, and R ¹ have the same meanings as above.

Preferred examples of the acid catalyst include p-toluenesulfonic acid.

Preferred examples of the solvent include chloroform, acetonitrile and dimethylformamide.

The salt represented by the formula (I2-c) can be prepared by the method described in Japanese Patent Application Laid-Open No. 2007-224008 and Japanese Patent Application Laid-Open No. 2012-224611, and examples of the salt include the salts shown below. include

Preferred examples of the compound represented by the formula (I2-d) include a compound represented by the following formula, which can be easily obtained in the market.

< Acid generator >

The salt (a) can function as an active ingredient in the acid generator in the resist composition. The acid generator comprising salt (a) is an aspect of the present invention. The acid generator may include one or more salts (a) together with other salts capable of generating an acid by radiation or the like.

<Resist composition>

The resist composition has an acid generator having the salt (a), and a resin having an acid labile group (which is sometimes referred to as “resin (A)”). The "acid labile group" herein means a group having a leaving group capable of being detached by contact with an acid, thereby forming a hydrophilic group such as a hydroxy group or a carboxy group.

The resist composition of the present invention may have, as an acid generator other than the salt (a), another acid generator (which is sometimes referred to as "acid generator (B)").

The resist composition preferably has a structure (which is sometimes referred to as "container (C)"). Further, the resist composition preferably has a solvent (which is sometimes referred to as "solvent (E)").

In addition, the resist composition of the present invention preferably contains a salt that generates an acid having a weaker acidity than that produced from acid generators (this salt is sometimes referred to as "weak acid salt (D)") and examples of this salt include salts in weak acid molecules.

< Resin (A) >

Resin (A) contains a structural unit having an acid labile group (which is sometimes referred to as "structural unit (a1)"). In addition, the resin (A) may preferably contain structural units other than the structural unit (a1). Examples of the structural unit other than the structural unit (a1) include a structural unit having no acid-labile group (which is sometimes referred to as "structural unit (s)").

<Structural unit (a1)>

The structural unit (a1) is derived from a monomer having an acid labile group, which is sometimes referred to as “monomer (a1)”.

In the resin (A), the acid-labile group contained in the structural unit (a1) is preferably one of the following formulas (1) and/or (2).

where R ^a1 to R ^a3 are each independently a C ₁ to C ₈ alkyl group, a C ₃ to C ₂₀ alicyclic hydrocarbon group, or a combination thereof, or R ^a1 And R ^a2 may combine with the carbon atom bonded thereto to form a C ₃ to C ₂₀ divalent alicyclic hydrocarbon group,

na represents an integer of 0 or 1,

* indicates a bond.

Here, R ^a1′ and R ^a2′ each independently represent a hydrogen atom or a C ₁ to C ₁₂ hydrocarbon group, and R ^a3′ represents a C ₁ to C ₂₀ hydrocarbon group, or R ^a2′ and R ^a3' may combine with the carbon atom and X to which they are bonded to form a divalent C ₃ to C ₂₀ heterocyclic group, and the methylene group included in the hydrocarbon group or the divalent heterocyclic group is an oxygen atom Or may be substituted with a sulfur atom,

X represents -O- or -S-,

* indicates a bond.

Examples of the alkyl group of R ^a1 to R ^a3 include a methyl group, an ethyl group, a propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, and n-octyl group.

Examples of the alicyclic hydrocarbon group of R ^a1 to R ^a3 include a cycloalkyl group, for example, a monocyclic group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and a decahydronaphthyl group, an adamantyl group, a norbornyl group and a polycyclic hydrocarbon group such as the following groups, wherein * represents a bond.

The alicyclic hydrocarbon group of R ^a1 to R ^a3 preferably has 3 to 16 carbon atoms.

Examples of the group combining an alkyl group and an alicyclic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, and a norbornylethyl group.

na is preferably an integer of 0.

When R ^a1 and R ^a2 combine together to form a divalent alicyclic hydrocarbon group, examples of the -C(R ^a1 )(R ^a2 )(R ^a3 ) group include the following groups. The divalent alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bond with -O-.

Specific examples of the group represented by formula (1) are, for example,

1,1-dialkylalkoxycarbonyl group (in formula (1), R ^a1 to R ^a3 are an alkyl group, preferably a tert-butoxycarbonyl group);

2-alkyladamantan-2-yloxycarbonyl group (in formula (1), R ^a1 , R ^a2 and a carbon atom form an adamantyl group, and R ^a3 is an alkyl group), and

1-(adamantan-1-yl)-1-alkylalkoxycarbonyl group (in formula (1), R ^a1 and R ^a2 are alkyl groups and R ^a3 is adamantyl group).

The hydrocarbon group of R ^a1' to R ^a3' includes any of an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining them.

Examples of the alkyl group and the alicyclic hydrocarbon group are the same as the above examples.

Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, and a biphenyl group. , a phenanthryl group, a 2,6-diethylphenyl group, an aryl group such as 2-methyl-6-ethylphenyl.

Examples of the divalent heterocyclic group formed by bonding R ^a2′ and R ^a3′ to each other include the following groups.

At least one of R ^a1' and R ^a2' is preferably a hydrogen atom.

Specific examples of the group represented by formula (2) include the following groups. * indicates a bond.

The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer having an acid labile group.

Among the (meth)acrylic monomers having an acid-labile group, a monomer having a C ₅ to C ₂₀ alicyclic hydrocarbon group is preferable. When a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in a resist composition, a resist composition having excellent resolution tends to be obtained.

Examples of the structural unit derived from the (meth)acrylic monomer having a group represented by the formula (1) are preferably represented by the following formulas (a1-0), (a1-1) and (a1-2) contains structural units. These may be used as a single structural unit or may be used as a combination of two or more types of structural units.

The structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1), and the structural unit represented by the formula (a1-2) are sometimes referred to as "structural unit (a1-0)", " The monomers from which the structural unit (a1-1)" and the "structural unit (a1-2)" are referred to as the structural unit (a1-0), the structural unit (a1-1), and the structural unit (a1-2) are , sometimes referred to as "monomer (a1-0)", "monomer (a1-1)" and "monomer (a1-2)", respectively,

Here, L ^a01 represents -O- or ^* -O-(CH ₂ ) _k01 -CO-O-,

k01 represents an integer of 1 to 7,

* represents a bond with -CO-,

R ^a01 represents a hydrogen atom or a methyl group, and

R ^a02 , R ^a03 and R ^a04 each independently represent a C ₁ to C ₈ alkyl group, a C ₃ to C ₁₈ alicyclic hydrocarbon group, or a combination thereof.

L ^a01 is preferably -O- or ^* -O-(CH ₂ ) _k01 -CO-O-, more preferably -O-, k01 is preferably an integer of 1 to 4, more preferably It is usually an integer of 1.

Examples of the alkyl group and the alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 and combinations thereof are the same as the examples of the group described for R ^a1 to R ^a3 in Formula (1).

The alkyl group of R ^a02 , R ^a03 and R ^a04 is preferably a C ₁ to C ₆ alkyl group.

The alicyclic hydrocarbon group of R ^a02 , R ^a03 and R ^a04 is preferably a C ₃ to C ₈ alicyclic hydrocarbon group, more preferably a C ₃ to C ₆ alicyclic hydrocarbon group.

The group combining an alkyl group and an alicyclic hydrocarbon group preferably has 18 or less carbon atoms. Examples of such a group include a methylcyclohexyl group, a dimethylcyclohexyl group, and a methylnorbornyl group.

R ^a02 and R ^a03 are preferably a C ₁ to C ₆ alkyl group, more preferably a methyl group or an ethyl group.

R ^a04 is preferably a C ₁ to C ₆ alkyl group or a C ₅ to C ₁₂ alicyclic hydrocarbon group, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group.

Here, L ^a1 and L ^a2 each independently represent -O- or ^* -O-(CH ₂ ) _k1 -CO-O-,

k1 represents an integer of 1 to 7,

* represents a bond with -CO-,

R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group,

R ^a6 and R ^a7 each independently represent a group that is a C ₁ to C ₈ alkyl group, a C ₃ to C ₁₈ alicyclic hydrocarbon group, or a combination thereof,

m1 represents an integer from 0 to 14,

n1 represents an integer from 0 to 10, and

n1' represents the integer of 0-3.

L ^a1 and L ^a2 are preferably -O- or ^* -O-(CH ₂ ) _k1' -CO-O-, more preferably -O-, k1' is preferably an integer of 1 to 4 , more preferably 1.

R ^a4 and R ^a5 are preferably a methyl group.

Examples of the alkyl group of R ^a6 and R ^a7 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n - Includes a heptyl group, a 2-ethylhexyl group, and an n-octyl group.

Examples of the alicyclic hydrocarbon group of R ^a6 and R ^a7 include a cycloalkyl group, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group. , a monocyclic hydrocarbon group such as a cyclooctyl group, a cycloheptyl group, and a cyclodecyl group; and decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1-(adamantan-1-yl)alkan-1-yl group, norbornyl group, methylnorbornyl group and isobornyl group and polycyclic hydrocarbon groups such as the group.

Examples of the group formed by combining the alkyl group and the alicyclic hydrocarbon group of R ^a6 and R ^a7 include an aralkyl group such as a benzyl group and a phenethyl group.

The alkyl group of R ^a6 and R ^a7 is preferably a C ₁ to C ₆ alkyl group.

The alicyclic hydrocarbon group of R ^a6 and R ^a7 is preferably a C ₃ to C ₈ alicyclic hydrocarbon group, more preferably a C ₃ to C ₆ alicyclic hydrocarbon group.

m1 is preferably an integer of 0 to 3, more preferably 0 or 1.

n1 is preferably an integer of 0 to 3, more preferably 0 or 1.

n1' is preferably 0 or 1, more preferably 1.

Examples of the monomer (a1-0) preferably include monomers represented by the following formulas (a1-0-1) to (a1-0-12), more preferably the following formulas (a1-0-) 1) to the monomers represented by formulas (a1-0-10) are included.

Examples of the structural unit (a1-0) above include a structural unit in which a methyl group corresponding to R ^a01 in the structural unit represented as above is substituted with a hydrogen atom.

Examples of the monomer (a1-1) include the monomer described in Japanese Patent Application Laid-Open No. 2010-204646. Among these, the monomer is preferably a monomer represented by formulas (a1-1-1) to (a1-1-8), more preferably formulas (a1-1-1) to (a1-1-4) ) as a monomer.

Examples of the monomer (a1-2) include 1-methylcyclopentan-1-yl (meth)acrylate, 1-ethylcyclopentan-1-yl (meth)acrylate, 1-methylcyclohexan-1-yl ( meth)acrylate, 1-ethylcyclohexan-1-yl (meth)acrylate, 1-ethylcycloheptan-1-yl (meth)acrylate, 1-ethylcyclooctan-1-yl (meth)acrylate; 1-isopropylcyclopentan-1-yl (meth)acrylate, and 1-isopropylcyclohexan-1-yl (meth)acrylate. Among these, the monomer is preferably a monomer represented by the formulas (a1-2-1) to (a1-2-12), more preferably the formulas (a1-2-3), (a1-2-4) ), a monomer represented by the formula (a1-2-9) or (a1-2-10), more preferably a monomer represented by the formulas (a1-2-3) and (a1-2-9) to be.

When the resin (A) contains the structural unit (a1-0) and/or the structural unit (a1-1) and/or the structural unit (a1-2), the total content thereof is the total structure of the resin (A). It is normally 10-95 mol% with respect to the total (100 mol%) of units, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

Further, examples of the structural unit (a1) having the group (1) include the structural unit represented by the formula (a1-3). The structural unit represented by formula (a1-3) is sometimes referred to as "structural unit (a1-3)". The monomer from which the structural unit (a1-3) is derived is sometimes referred to as "monomer (a1-3)".

Here, R ^a9 represents a C ₁ to C ₃ aliphatic hydrocarbon group which may have a hydroxyl group, a carboxy group, a cyano group, -COOR ^a13 or a hydrogen atom.

R ^a13 represents a C ₁ to C ₈ aliphatic hydrocarbon group, a C ₃ to C ₂₀ alicyclic hydrocarbon group, or a group formed by combining them, and a hydrogen atom included in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is, may be substituted with a hydroxyl group, and the methylene group contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group may be substituted with an oxygen atom or a carbonyl group,

R ^a10 , R ^a11 and R ^a12 each independently represent a C ₁ to C ₈ alkyl hydrocarbon group, a C ₃ to C ₂₀ alicyclic hydrocarbon group, or a group formed by combining them, or R ^a10 and R ^a11 are their By bonding with the carbon atom bonded to, it may form a divalent hydrocarbon group of C ₁ to C ₂₀ .

where -COOR ^a13 Examples of the group include a group in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group.

Examples of the aliphatic hydrocarbon group which may have a hydroxyl group for R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group and a 2-hydroxyethyl group.

Examples of the C ₁ to C ₈ aliphatic hydrocarbon group of R ^a13 include a methyl group, an ethyl group, a propyl group, an isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group Sil group, n-heptyl group, 2-ethylhexyl group, n-octyl group is included.

Examples of the C ₃ to C ₂₀ alicyclic hydrocarbon group of R ^a13 include a cyclopentyl group, a cyclopropyl group, an adamantyl group, an adamantylmethyl group, a 1-adamantyl-1-methylethyl group, and a 2-oxo-oxo group. and a lan-3-yl group and a 2-oxo-oxolan-4-yl group.

Examples of the alkyl group of R ^a10 to R ^a12 include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n- a heptyl group, a 2-ethylhexyl group, and an n-octyl group.

Examples of the alicyclic hydrocarbon group of R ^a10 to R ^a12 include a cycloalkyl group, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, monocyclic hydrocarbon groups such as a cyclooctyl group and a cyclodecyl group; and decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1-(adamantan-1-yl)alkan-1-yl group, norbornyl group, methylnorbornyl group and isobornyl group and polycyclic hydrocarbon groups such as the group.

Examples of the group -C(R ^a10 )(R ^a11 )(R ^a12 ) include the following groups when R ^a10 and R ^a11 are bonded together with the carbon atom to which they are bonded to form a divalent hydrocarbon group.

Examples of the monomer (a1-3) are 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene -2-carboxylic acid 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyl-2-adamantyl, 5-norbornene-2-carboxylic acid 2-ethyl-2-adamantyl , 5-norbornene-2-carboxylic acid 1-(4-methylcyclohexyl)-1-methylethyl, 5-norbornene-2-carboxylic acid 1-(4-hydroxycyclohexyl)-1-methyl Ethyl, 5-norbornene-2-carboxylic acid 1-methyl-1-(4-oxocyclohexyl)ethyl and 5-norbornene-2-carboxylic acid 1-(1-adamantyl)-1-methyl contains ethyl.

Since the resin (A) having the structural unit (a1-3) has a bulky structure, the resolution of the resulting resist composition can be improved, and a rigid norbornane ring is introduced into the main chain of the resin (A). Therefore, the dry etching resistance of the resist composition obtained can be improved.

When the resin (A) contains the structural unit (a1-3), the content is usually 10 to 95 mol% with respect to the total (100 mol%) of all structural units of the resin (A), preferably is 15 to 90 mol%, more preferably 20 to 85 mol%.

Examples of the structural unit (a1) having the group (2) include the structural unit represented by the formula (a1-4). The structural unit is sometimes referred to as “structural unit (a1-4)”.

Here, R ^a32 represents a hydrogen atom, a halogen atom, or a C ₁ to C ₆ alkyl group which may have a halogen atom.

In each occurrence, R ^a33 is independently a halogen atom, a hydroxy group, a C ₁ to C ₆ alkyl group, a C ₁ to C ₆ alkoxy group, a C ₂ to C ₄ acyl group, a C ₂ to C ₄ acyloxy group , an acryloyloxy group or a methacryloyloxy group.

la represents an integer of 0 to 4.

R ^a34 and R ^a35 each independently represent a hydrogen atom or a C ₁ to C ₁₂ hydrocarbon group, and

R ^a36 represents a C ₁ to C ₂₀ hydrocarbon group, or R ^a35 and R ^a36 may be bonded together with CO bonded thereto to form a divalent C ₂ to C ₂₀ hydrocarbon group, and the hydrocarbon group and the The methylene group contained in the divalent hydrocarbon group may be substituted with an oxygen atom or a sulfur atom.

Examples of the alkyl group of R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group and a hexyl group. The alkyl group is preferably a C ₁ to C ₄ alkyl group, more preferably a methyl group or an ethyl group, and more preferably a methyl group.

Examples of the halogen atom of R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

Examples of the alkyl group which may have a halogen atom are trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1,2,2-tetrafluoro Ethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4 -octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n-pentyl group, n-hexyl group and n-perfluorohexyl group.

Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. The alkoxy group is preferably a C ₁ to C ₄ alkoxy group, more preferably a methoxy group or an ethoxy group, and more preferably a methoxy group.

Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group and a butyryloxy group.

Examples of the hydrocarbon group of R ^a34 and R ^a35 are the same as those described for R ^a1' to R ^a2' in formula (2).

Examples of the hydrocarbon group of R ^a36 include a C ₁ to C ₁₈ alkyl group, a C ₃ to C ₁₈ alicyclic hydrocarbon group, a C ₃ to C ₁₈ aromatic hydrocarbon group, or a group formed by combining them.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.

R ^a33 is preferably a C ₁ to C ₄ alkoxy group, more preferably a methoxy group and an ethoxy group, more preferably a methoxy group.

la is preferably 0 or 1, more preferably 0.

R ^a34 is preferably a hydrogen atom.

R ^a35 is preferably a C ₁ to C ₁₂ hydrocarbon group, more preferably a methyl group or an ethyl group.

The hydrocarbon group of R ^a36 is preferably a C ₁ to C ₁₈ alkyl group, a C ₃ to C ₁₈ alicyclic hydrocarbon group, a C ₆ to C ₁₈ aromatic hydrocarbon group, or a group formed by combining them, more preferably a C ₁ to C ₁₈ alkyl group, a C ₃ to C ₁₈ alicyclic aliphatic hydrocarbon group, or a C ₇ to C ₁₈ aralkyl group. The alkyl group and alicyclic hydrocarbon group of R ^a36 are preferably unsubstituted. When the aromatic hydrocarbon group of R ^a36 has a substituent, the substituent is preferably a C ₆ to C ₁₀ aryloxy group.

Examples of the monomer deriving the structural unit (a1-4) include the monomer described in Japanese Patent Application Laid-Open No. 2010-204646. Among these, the monomer is preferably a monomer represented by the following formulas (a1-4-1) to (a1-4-7), more preferably formulas (a1-4-1) to ( a1-4-5).

When the resin (A) contains the structural unit (a1-4), the content is preferably 10-95 mol% with respect to the total (100 mol%) of all structural units of the resin (A), More preferably, it is 15-90 mol%, More preferably, it is 20-85 mol%.

Examples of the structural unit having an acid labile group include a structural unit represented by formula (a1-5). This structural unit is sometimes referred to as "structural unit (a1-5)".

Here, R ^a8 represents a C ₁ to C ₆ alkyl group which may have a halogen atom, a hydrogen atom, or a halogen atom.

Z ^a1 represents a single bond or *-(CH ₂ ) _h3 -CO-L ⁵⁴ -,

h3 represents an integer of 1 to 4,

* represents a bond with L ⁵¹ ,

L ⁵¹ , L ⁵² , and L ⁵³ each independently represent -O- or -S-,

s1 represents an integer of 1 to 3,

s1' represents the integer of 0-3.

In the formula (a1-5), R ^a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.

L ⁵¹ is preferably -O-,

L ⁵² and L ⁵³ are each independently preferably -O- or -S-, More preferably, one is -O- and the other is -S-.

s1 is preferably 1,

s1' is preferably an integer from 0 to 2.

Z ^a1 is preferably a single bond or *-CH ₂ -CO-O-.

Examples of the monomer deriving the structural unit (a1-5) include the monomer described in Japanese Patent Application Laid-Open No. 2010-61117. Among them, the monomer is preferably a monomer represented by the following formulas (a1-5-1) to (a1-5-4), and more preferably a monomer represented by formulas (a1-5-1) to (a1-). It is a monomer represented by 5-2).

When the resin (A) contains the structural unit (a1-5), the content is usually 1 to 50 mol% with respect to the total (100 mol%) of all structural units of the resin (A), preferably is 3 to 45 mol%, more preferably 5 to 40 mol%.

Examples of the structural unit (a1) having an acid labile group in the resin (A) are preferably the structural unit (a1-0), the structural unit (a1-1), the structural unit (a1-2) and the structural unit (a1-) 5) at least one kind, more preferably two or more, more preferably a combination of a structural unit (a1-1) and a structural unit (a1-2), and a structural unit (a1-1) from the structural unit selected from the group consisting of 5). ) and a combination of a structural unit (a1-5), a combination of a structural unit (a1-1) and a structural unit (a1-0), a combination of a structural unit (a1-2) and a structural unit (a1-0), a structural unit a combination of (a1-5) and a structural unit (a1-0), a structural unit (a1-0), a combination of a structural unit (a1-1) and a structural unit (a1-2), a structural unit (a1-0); a combination of the structural unit (a1-1) and the structural unit (a1-5), particularly preferably the combination of the structural unit (a1-1) and the structural unit (a1-2) and the structural unit (a1-1) and the structure It is a combination of units (a1-5).

<Structural unit without acid labile group (s)>

The structural unit (s) is derived from a monomer having no acid labile group, which is sometimes referred to as “monomer (s)”.

For the monomer (s) from which the structural unit (s) is derived, a monomer having no known acid-labile group can be used.

As the structural unit (s), a structural unit having a hydroxyl group or a lactone ring and not having an acid labile group is preferable. A structural unit having a hydroxyl group and not having an acid labile group (such a structural unit is sometimes referred to as "structural unit (a2)") and/or a structural unit having a lactone ring and not having an acid labile group (such as When a resin including a structural unit derived from the structural unit (which is sometimes referred to as "structural unit (a3)") is used, the resolution of the resist pattern and the adhesion of the resist with the substrate tend to be improved.

<Structural unit (a2)>

The structural unit (a2) having a hydroxyl group may be an alcoholic hydroxyl group or a phenolic hydroxyl group.

For the resist composition, when a KrF excimer laser (248 nm), or a high energy ray such as an electron beam or EUV (ultra-ultraviolet light) is used, it is preferable to use, as the structural unit (a2), a structural unit having a phenolic hydroxyl group. do.

When an ArF excimer laser (193 nm) is used, it is preferable to use a structural unit having an alcoholic hydroxyl group as the structural unit (a2), and it is more preferable to use a structure represented by the formula (a2-1).

The structural unit (a2) may be used as a single structural unit or as a combination of two or more types of structural units.

The structural unit (a2) having a phenolic hydroxyl group includes a structural unit represented by formula (a2-0) (which is sometimes referred to as “structural unit (a2-0)”).

Here, R ^a30 represents a hydrogen atom, a halogen atom or a C ₁ to C ₆ alkyl group which may have a halogen atom,

In each case, R ^a31 is a halogen atom, a hydroxyl group, a C ₁ to C ₆ alkyl group, a C ₁ to C ₆ alkoxy group, a C ₂ to C ₄ acyl group, a C ₂ to C ₄ acyloxy group, acryl represents a loyloxy group or a methacryloyloxy group,

ma represents an integer of 0 to 4.

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an n-pentyl group, and an n-hexyl group.

Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom.

Examples of the C ₁ to C ₆ alkyl group that may have a halogen atom for R ^a30 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 1,1,1-trifluoroethyl group, 1, 1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2, 2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, n -pentyl group, n-hexyl group, and n-perfluorohexyl group.

R ^a30 is preferably a hydrogen atom or a C ₁ to C ₄ alkyl group, more preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group.

Examples of the C ₁ to C ₆ alkoxy group of R ^a31 include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group and a hexyloxy group. R ^a31 is preferably a C ₁ to C ₄ alkoxy group, more preferably a methoxy group or an ethoxy group, and more preferably a methoxy group.

Examples of the acyl group include an acetyl group, a propionyl group and a butyryl group.

Examples of the acyloxy group include an acetyloxy group, a propionyloxy group and a butyryloxy group.

ma is preferably 0, 1 or 2, more preferably 0 or 1, more preferably 0.

The structural unit (a2-0) having a phenolic hydroxyl group is preferably a structural unit shown below.

Especially, the structural unit represented by Formula (a2-0-1) or Formula (a2-0-2) is preferable.

Examples of the monomer deriving the structural unit (a2-0) include the monomer described in Japanese Patent Application Laid-Open No. 2010-204634.

The resin (A) comprising the structural unit (a2) having a phenolic hydroxy group is, for example, a monomer in which the phenolic hydroxy group of the monomer deriving the structural unit (a2) having a phenolic hydroxy group is protected with a suitable protecting group. It can be manufactured by carrying out a polymerization reaction using it and carrying out a deprotection process after that. The deprotection treatment is performed in such a way that the acid labile group in the structural unit (a1) is not significantly damaged. Examples of the protecting group for the phenolic hydroxy group include an acetyl group.

When resin (A) contains the structural unit (a2-0) which has a phenolic hydroxyl group, the content rate is 5-95 normally with respect to the total (100 mol%) of all structural units of resin (A). It is mol%, Preferably it is 10-80 mol%, More preferably, it is 15-80 mol%.

Examples of the structural unit (a2) having an alcoholic hydroxyl group include a structural unit represented by formula (a2-1) (which is sometimes referred to as “structural unit (a2-1)”).

Here, L ^a3 represents -O- or *-O-(CH ₂ ) _k2 -CO-O-,

k2 represents an integer of 1 to 7,

* represents a bond with -CO-,

R ^a14 represents a hydrogen atom or a methyl group,

R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group, and

o1 represents the integer of 0-10.

In the formula (a2-1), L ^a3 is preferably -O-, -O-(CH ₂ ) _f1 -CO-O-, more preferably -O-, wherein f1 is 1 to 4 of represents an integer.

R ^a14 is preferably a methyl group.

R ^a15 is preferably a hydrogen atom.

R ^a16 is preferably a hydrogen atom or a hydroxy group.

o1 becomes like this. Preferably it is an integer of 0-3, More preferably, it is an integer of 0 or 1.

Examples of the monomer deriving the structural unit (a2-1) include the monomer described in Japanese Patent Application Laid-Open No. 2010-204646. Among these, the monomer is preferably a monomer represented by formulas (a2-1-1) to (a2-1-6), more preferably formulas (a2-1-1) to (a2-1-) It is a structural unit represented by 4), More preferably, it is a structural unit represented by a formula (a2-1-1) and a formula (a2-1-3).

Examples of the monomer deriving the structural unit (a2) having an alcoholic hydroxy group include the monomer described in Japanese Patent Application Laid-Open No. 2010-204646.

When the resin (A) contains the structural unit (a2) having an alcoholic hydroxyl group, the content is usually 1 to 45 mol% with respect to the total (100 mol%) of all structural units of the resin (A), Preferably it is 1-40 mol%, More preferably, it is 1-35 mol%, More preferably, it is 2-20 mol%.

< Structural unit (a3) >

The lactone ring included in the structural unit (a3) may be a monocyclic compound such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, and may be a condensed ring of another ring and a monocyclic lactone ring. . Examples of the lactone ring preferably include a γ-butyrolactone ring, an adamantane lactone ring, or a bridging ring including a γ-butyrolactone ring structure.

Examples of the structural unit (a3) include structural units arbitrarily represented by formulas (a3-1), (a3-2), (a3-3) and (a3-4). These structural units may be used as a single unit or may be used as a combination of two or more types of units.

Here, L ^a4 represents *-O- or *-O-(CH ₂ ) _k3 -CO-O-, k3 represents an integer of 1 to 7, * represents a bond with a carbonyl group,

R ^a18 represents a hydrogen atom or a methyl group,

R ^a21 in each case represents a C ₁ to C ₄ aliphatic hydrocarbon group, and

p1 represents an integer from 0 to 5,

L ^a5 represents *-O- or *-O-(CH ₂ ) _k3 -CO-O-, k3 represents an integer of 1 to 7, * represents a bond with a carbonyl group,

R ^a19 represents a hydrogen atom or a methyl group,

R ^a22 in each case represents a carboxy group, a cyano group or a C ₁ to C ₄ aliphatic hydrocarbon group,

q1 represents an integer from 0 to 3,

L ^a6 represents *-O- or *-O-(CH ₂ ) _k3 -CO-O-, k3 represents an integer of 1 to 7, * represents a bond with a carbonyl group,

R ^a20 represents a hydrogen atom or a methyl group,

R ^a23 in each case represents a carboxy group, a cyano group or a C ₁ to C ₄ aliphatic hydrocarbon group, and

r1 represents an integer from 0 to 3,

R ^a24 represents a C ₁ to C ₆ alkyl group which may have a halogen atom, a hydrogen atom or a halogen atom,

L ^a7 is a single bond, *-L ^a8 -O-, *-L ^a8 -CO-O-, *-L ^a8 -CO-OL ^a9 -CO-O- or *-L ^a8 -O-CO-L ^a9 -O-; * represents a bond with a carbonyl group, and

L ^a8 and L ^a9 each independently represent a C ₁ to C ₆ alkanediyl group.

Examples of the aliphatic hydrocarbon group of R ^a21 , R ^a22 and R ^a23 include an alkyl group, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group and a tert-butyl group.

Examples of the halogen atom of R ^a24 include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom,

Examples of the alkyl group of R ^a24 include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group and n-hexyl group, preferably Preferably, a C ₁ to C ₄ alkyl group is mentioned, and more preferably a methyl group or an ethyl group is included.

Examples of the alkyl group having a halogen atom for R ^a24 include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, purple Luoro includes a tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.

L^a8 and L^a9Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, Hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2-methylbutane-1,4-diyl groups.

In formulas (a3-1) to (a3-3), L ^a4 to L ^a6 are each independently of each other, Preferably -O- and k3 are *-O-(CH) represented by an integer of 1 to 4 ₂ ) _k3 -CO-O-, more preferably -O- or *-O-CH ₂ -CO-O-, more preferably *-O-.

R ^a18 to R ^a21 are preferably a methyl group.

R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group or a methyl group.

p1, q1 and r1 each independently represent an integer of preferably 0 to 2, and more preferably 0 or 1.

In the formula (a3-4), R ^a24 is preferably a hydrogen atom or a C ₁ to C ₄ alkyl group, more preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom or a methyl group.

L ^a7 is preferably a single bond or *-L ^a8 -CO-O-, and more preferably a single bond, -CH ₂ -CO-O- or -C ₂ H ₄ -CO-O-.

Examples of the monomer deriving the structural unit (a3) include a monomer described in Japanese Patent Application Laid-Open No. 2010-204646, a monomer described in Japanese Patent Application Laid-Open No. 2000-122294, and a monomer described in Japanese Patent Application Laid-Open No. 2012-41274. monomers. Among these, the structural units are preferably the following formulas (a3-1-1) to (a3-1-4), (a3-2-1) to (a3-2-4), and formula (a3) Structural units represented by -3-1) to formulas (a3-3-4) and (a3-4-1) to (a3-4-12), more preferably formula (a3-1-1) ) to the structures represented by the formulas (a3-1-2) and (a3-2-3), (a3-2-4), (a3-4-1) and (a3-4-2) It is a unit, More preferably, it is a structural unit represented by a formula (a3-1-1), a formula (a3-2-3), or a formula (a3-4-2).

When the resin (A) contains the structural unit (a3), the total content is preferably 5 to 70 mol%, more preferably 5 to 70 mol%, based on the total (100 mol%) of all structural units of the resin (A). Preferably it is 10-65 mol%, More preferably, it is 10-60 mol%.

Each content rate of the structural unit represented by a formula (a3-1), a formula (a3-2), a formula (a3-3), and a formula (a3-4) is the sum total (100 mol) of all the structural units of resin (A) %), preferably 5 to 60 mol%, more preferably 5 to 50 mol%, more preferably 10 to 50 mol%.

< Other structural units (t) >

The resin (A) may contain structural units other than the structural unit (a1) and structural unit (s) described above (which is sometimes referred to as “structural unit (t)”). Examples of the structural unit (t) are, in addition to the structural unit (a1) and the structural unit (a3), a structural unit having a halogen atom (which is sometimes referred to as "structural unit (a4)") and a structural unit having a non-trivial hydrocarbon group ( It is sometimes referred to as "structural unit (a5)").

< Structural unit (a4) >

The structural unit having a halogen atom preferably has a fluorine atom.

Examples of the structural unit (a4) include the structural unit represented by formula (a4-0).

Here, R ⁵ represents a hydrogen atom or a methyl group,

L ⁵ represents a single bond or a C ₁ to C ₄ aliphatic saturated hydrocarbon group,

L ³ represents a C ₁ to C ₈ perfluoroalkanediyl group or a C ₅ to C ₁₂ perfluorocycloalkanediyl group, and

R ⁶ represents a hydrogen atom or a fluorine atom.

Examples of the aliphatic saturated hydrocarbon group of L ⁵ include a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group; and a branched alkanediyl group such as a group in which the linear alkanediyl group has a side chain of an alkyl group (eg, a methyl group, an ethyl group), for example, an ethane-1,1-diyl group, a propane-1,2-diyl group , butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.

Examples of the perfluoroalkanediyl group of L ³ are difluoromethylene group, perfluoroethylene group, perfluoroethylfluoromethylene group, perfluoropropane-1,3-diyl group, perfluoropropane- 1,2-diyl group, perfluoropropane-2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1, 2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2-diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6- Diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7-diyl group, perfluoroheptane-2,2-diyl group , perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, purple a luorooctane-3,3-diyl group and a perfluorooctane-4,4-diyl group.

Examples of the perfluorocycloalkanediyl group of L ³ include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group and a perfluoroadamantanediyl group.

L ⁵ is preferably a single bond, a methylene group, or an ethylene group, and more preferably a single bond or a methylene group.

L ³ is preferably a C ₁ to C ₆ perfluoroalkanediyl group, and more preferably a C ₁ to C ₃ perfluoroalkanediyl group.

Examples of the structural unit (a4-0) include structural units represented by formulas (a4-0-1) to (a4-0-32).

Examples of the structural unit (a4) include structural units represented by formula (a4-1).

Here, R ^a41 represents a hydrogen atom or a methyl group,

R ^a42 represents an optionally substituted C ₁ to C ₂₀ hydrocarbon group, and the methylene group contained in the hydrocarbon group may be substituted with an oxygen atom or a carbonyl group,

A ^a41 represents an optionally substituted C ₁ to C ₆ alkanediyl group or a group represented by formula (a-g1),

where s represents 0 or 1,

A ^a42 and A ^a44 each independently represent an optionally substituted C ₁ to C ₅ aliphatic hydrocarbon group,

A ^a43 represents a single bond or an optionally substituted C ₁ to C ₅ aliphatic hydrocarbon group, and

X ^a41 and X ^a42 each independently represent -O-, -CO-, -CO-O- or -O-CO-,

provided that the total number of carbon atoms included in the groups of A ^{a42 , A a43 ,} A ^a44 , X ^a41 and X ^a42 is 6 or less, and

At least one of A ^a41 and R ^a42 has a halogen atom as a substituent,

* and ** denote a bond, and * denotes a bond with -O-CO-R ^a42 .

Examples of the hydrocarbon group for R ^a42 include chain and cyclic aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups of combinations thereof.

Examples of the chain aliphatic hydrocarbon group are methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-decyl group, n- and alkyl groups, such as dodecyl group, n-pentadecyl group, n-hexadecyl group, n-heptadecyl group and n-octadecyl group. Examples of the cyclic alicyclic hydrocarbon group include a monocyclic hydrocarbon group, for example, a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and decahydronaphthyl group, adamantyl group, norbornyl group, and polycyclic hydrocarbon groups such as the following groups. * indicates a bond.

Examples of the aromatic hydrocarbon group include an aryl group such as a phenyl group, a naphthyl group, an anthryl group, a biphenylyl group, a phenanthryl group and a fluorenyl group.

The hydrocarbon group of R ^a42 is preferably a group of chain and cyclic aliphatic hydrocarbon groups and combinations thereof. The hydrocarbon group may have a carbon-carbon unsaturated bond, and is preferably a chain or cyclic aliphatic saturated hydrocarbon group or a combination thereof.

Examples of the substituent of R ^a42 include a fluorine atom or a group represented by formula (a-g3).

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a fluorine atom.

Here, X ^a43 represents an oxygen atom, a carbonyl group, a carbonyloxy group or an oxycarbonyl group,

A ^a45 represents a C ₁ to C ₁₇ aliphatic hydrocarbon group having a halogen atom, and

* represents a bond with a carbonyl group.

Examples of the aliphatic hydrocarbon group of A ^a45 are the same as those of the group of R ^a42 .

R ^a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and/or an aliphatic hydrocarbon group having a group represented by the formula (a-g3).

When R ^a42 is an aliphatic hydrocarbon group having a halogen atom, an aliphatic hydrocarbon group having a fluorine atom is preferable, a perfluoroalkyl group or a perfluorocycloalkyl group is more preferable, and a C ₁ to C ₆ perfluoroalkyl group is more preferable. and a C ₁ to C ₃ perfluoroalkyl group is particularly preferred.

Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluoro contains a rooctyl group.

Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group.

When R ^a42 is an aliphatic hydrocarbon group having a group represented by the formula (a-g3), the total number of carbon atoms in the aliphatic hydrocarbon group including the group represented by the formula (a-g3) is preferably 15 or less, more Preferably it is 12 or less. The number of groups represented by the formula (a-g3) is preferably one when the group represented by the formula (a-g3) is a substituent.

The aliphatic hydrocarbon having a group represented by the formula (a-g3) is more preferably a group represented by the formula (a-g2).

Here, A ^a46 represents a C ₁ to C ₁₇ aliphatic hydrocarbon group which may have a halogen atom.

X ^a44 represents a carbonyloxy group or an oxycarbonyl group.

A ^a47 represents a C ₁ to C ₁₇ aliphatic hydrocarbon group which may have a halogen atom,

provided that the total number of carbon atoms included in the groups of A ^a46 , X ^a44 and A ^a47 is 18 or less,

At least one of A ^a46 and A ^a47 has a halogen atom, and

* represents a bond with a carbonyl group.

The number of carbon atoms in the aliphatic hydrocarbon group of A ^a46 is preferably 1 to 6, more preferably 1 to 3.

The aliphatic hydrocarbon group of A ^a47 preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and more preferably a cyclohexyl group or an adamantyl group as the aliphatic hydrocarbon group.

The preferable structure, *-A ^a46 -X ^a44 -A ^a47 represented by the formula (a-g2) includes the following.

Examples of the alkanediyl group of A ^a41 include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. a linear alkanediyl group, such as a diary;

Propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4 - Includes branched alkanediyl groups, such as diyl groups.

Examples of the substituent of the alkanediyl group of A ^a41 include a hydroxyl group and a C ₁ to C ₆ alkoxy group.

delete

A ^a41 is preferably a C ₁ to C ₄ alkanediyl group, more preferably a C ₂ to C ₄ alkanediyl group, and more preferably an ethylene group.

In the group represented by the formula (a-g1) (which is sometimes referred to as "group (a-g1)"), examples of the aliphatic hydrocarbon group of A ^a42 , A ^a43 and A ^a44 are a methylene group, an ethylene group , propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-di diyl, 2-methylpropane-1,2-diyl groups.

Examples of the substituent of the aliphatic hydrocarbon group of A ^a42 , A ^a43 and A ^a44 include a hydroxyl group and a C ₁ to C ₆ alkoxy group.

s is preferably zero.

Examples of the group (a-g1) in which X ^a42 represents an oxygen atom include the following groups. In the formula, * and ** each represent a bond, and ** denotes a bond with -O-CO-R ^a42 .

Examples of the group (a-g1) in which X ^a42 represents a carbonyl group include the following groups.

Examples of the group (a-g1) in which X ^a42 represents a carbonyloxy group include the following groups.

Examples of the group (a-g1) in which X ^a42 represents an oxycarbonyl group include the following groups.

The structural unit represented by the formula (a4-1) is preferably a structural unit represented by the formulas (a4-2) and (a4-3).

Here, R ^f1 represents a hydrogen atom or a methyl group,

A ^f1 represents a C ₁ to C ₆ alkanediyl group, and

R ^f2 represents a C ₁ to C ₁₀ hydrocarbon group having a fluorine atom.

Examples of the alkanediyl group of A ^f1 include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. a linear alkanediyl group, such as a diyl group and a hexane-1,6-diyl group;

1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, 2- branched alkanediyl groups, such as methylbutane-1,4-diyl groups.

The hydrocarbon group of R ^f2 includes an aliphatic hydrocarbon group and an aromatic hydrocarbon group. The aliphatic hydrocarbon group includes groups of chain, cyclic, and combinations thereof. The aliphatic hydrocarbon group is preferably an alkyl group or an alicyclic hydrocarbon group.

Examples of the alkyl group include a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group and 2- ethylhexyl group.

Examples of the alicyclic hydrocarbon group include any of a monocyclic group and a polycyclic formula. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cycloheptyl group and a cyclo cycloalkyl groups, such as decyl groups. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 2-alkyladamantan-2-yl group, 1-(adamantan-1-yl)alkan-1-yl group, norbor nyl group, methylnorbornyl group and isobornyl group.

Examples of the hydrocarbon group having a fluorine atom for R ^f2 include an alkyl group having a fluorine atom and an alicyclic hydrocarbon group having a fluorine atom.

Specific examples of the alkyl group having a fluorine atom are difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, purple Luoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluoro)methyl-2,2,2-trifluoro Roethyl group, 2-(perfluoropropyl)ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3 ,3,4,4,5,5-decafluoropentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group , 2- (perfluorobutyl) ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4 ,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group and perfluorohexyl group, such as fluorinated alkyl group.

Examples of the alicyclic hydrocarbon group having a fluorine atom include a fluorinated cycloalkyl group, such as a perfluorocyclohexyl group and a perfluoroadamantyl group.

In the formula (a4-2), A ^f1 is preferably a C ₂ to C ₄ alkanediyl group, more preferably an ethylene group.

R ^f2 is preferably a C ₁ to C ₆ fluorinated alkyl group.

Here, R ^f11 represents a hydrogen atom or a methyl group,

A ^f11 represents a C ₁ to C ₆ alkanediyl group,

A ^f13 represents a C ₁ to C ₁₈ aliphatic hydrocarbon group which may have a fluorine atom,

X ^f12 represents a carbonyloxy group or an oxycarbonyl group,

A ^f14 represents a C ₁ to C ₁₇ aliphatic hydrocarbon group which may have a fluorine atom,

However, at least one of A ^f13 and A ^f14 represents an aliphatic hydrocarbon group having a fluorine atom.

Examples of the alkanediyl group of A ^f11 are the same as those of the alkanediyl group of A ^f1 .

Examples of the aliphatic hydrocarbon group of A ^f13 include any of a divalent chain or cyclic hydrocarbon group or a combination thereof. This aliphatic hydrocarbon may have a carbon-carbon unsaturated bond, Preferably it is an aliphatic saturated hydrocarbon group.

The aliphatic hydrocarbon group which may have a fluorine atom as A ^f13 is an aliphatic saturated hydrocarbon group which may have a fluorine atom, Preferably it is a perfluoro alkanediyl group.

Examples of the divalent chain aliphatic hydrocarbon group which may have a fluorine atom include an alkanediyl group such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group and a pentanediyl group; perfluoroalkanediyl groups, such as difluoromethylene group, perfluoroethylene group, perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.

The divalent cyclic aliphatic hydrocarbon group which may have a fluorine atom may be any of monocyclic and polycyclic.

Examples of the monocyclic aliphatic hydrocarbon group include a cyclohexanediyl group and a perfluorocyclohexanediyl group.

Examples of the polycyclic aliphatic hydrocarbon group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

Examples of the aliphatic hydrocarbon group of A ^f14 include any one of a chain and cyclic hydrocarbon group, or a combination thereof. This aliphatic hydrocarbon group may have a carbon-carbon unsaturated bond, Preferably it is an aliphatic saturated hydrocarbon group.

The aliphatic hydrocarbon group which may have a fluorine atom as A ^f14 is preferably an aliphatic saturated hydrocarbon group which may have a fluorine atom.

Examples of the chain aliphatic hydrocarbon group which may have a halogen atom are trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 1,1,1-trifluoroethyl group, 1,1,2,2 -tetrafluoroethyl group, ethyl group, perfluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 ,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group and perfluorooctyl group.

The cyclic aliphatic hydrocarbon group which may have a halogen atom may be any monocyclic or polycyclic group. Examples of the group containing a monocyclic aliphatic hydrocarbon group include a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, and a perfluorocyclohexyl group. Examples of the group containing the polycyclic aliphatic hydrocarbon group include an adamantyl group, an adamantylmethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group and a perfluoroadamantylmethyl group.

In the formula (a4-3), A ^f11 is preferably an ethylene group.

The aliphatic hydrocarbon group of A ^f13 is preferably a C ₁ to C ₆ aliphatic hydrocarbon group, and more preferably a C ₂ to C ₃ aliphatic hydrocarbon group.

The aliphatic hydrocarbon group of A ^f14 is preferably a C ₃ to C ₁₂ aliphatic hydrocarbon group, and more preferably a C ₃ to C ₁₀ aliphatic hydrocarbon group. Among them, A ^f14 is preferably a group containing a C ₃ to C ₁₂ alicyclic hydrocarbon group, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group.

Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-22).

Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-22).

Examples of the structural unit (a4) include the structural unit represented by the formula (a4-4).

Here, R ^f21 represents a hydrogen atom or a methyl group,

A ^f21 represents -(CH ₂ ) _j1 -, -(CH ₂ ) _j2 -O-(CH ₂ ) _j3 - or -(CH ₂ ) _j4 -CO-O-(CH ₂ ) _j5 -,

j1 to j5 each independently represent an integer of 1 to 6, and

R ^f22 represents a C ₁ to C ₁₀ hydrocarbon group having a fluorine atom.

Examples of the hydrocarbon group having a fluorine atom of R ^f22 are the same as the examples of the hydrocarbon group described for R ^f2 in the formula (a4-2). R ^f22 is preferably a C ₁ to C ₁₀ alkyl group having a fluorine atom or a C ₃ to C ₁₀ alicyclic hydrocarbon group having a fluorine atom, more preferably a C ₁ to C ₁₀ alkyl group having a fluorine atom and more preferably a C ₁ to C ₆ alkyl group having a fluorine atom.

In the formula (a4-4), A ^f21 is preferably -(CH ₂ ) _j1 -, more preferably an ethylene group or a methylene group, and still more preferably a methylene group.

Examples of the structural unit represented by formula (a4-4) include the following.

When the resin (A) has the structural unit (a4), the content is usually 1 to 20 mol%, preferably 2 to the total (100 mol%) of all structural units of the resin (A). to 15 mol%, more preferably 3 to 10 mol%.

<Structural unit (a5)>

Examples of the non-departing hydrocarbon group of the structural unit (a5) include a straight-chain, branched or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a structural unit containing an alicyclic hydrocarbon group.

The structural unit (a5) is, for example, a structural unit represented by formula (a5-1).

Here, R ⁵¹ represents a hydrogen atom or a methyl group,

R ⁵² represents a C ₃ to C ₁₈ alicyclic hydrocarbon group, and a hydrogen atom included in the alicyclic hydrocarbon group may be substituted with a C ₁ to C ₈ aliphatic hydrocarbon group or a hydroxyl group, provided that the carbon bonded to L ⁵¹ A hydrogen atom included in the atom is not substituted with a C ₁ to C ₈ aliphatic hydrocarbon group, and

L ⁵¹ represents a single bond or a C ₁ to C ₁₈ divalent saturated hydrocarbon group, and the methylene group contained in the saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group.

Examples of the alicyclic hydrocarbon group for R ⁵² include any of a monocyclic group and a polycyclic group. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group. Examples of the polycyclic hydrocarbon group include an adamantyl group and a norbornyl group.

Examples of the C ₁ to C ₈ aliphatic hydrocarbon group include a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group , n-heptyl group, 2-ethylhexyl group, and an alkyl group, such as n-octyl group.

Examples of the alicyclic hydrocarbon group having a substituent include a 3-hydroxyadamantyl group and a 3-methyladamantyl group.

R ⁵² is preferably an unsubstituted C ₃ to C ₁₈ alicyclic hydrocarbon group, and more preferably an adamantyl group, a norbornyl group and a cyclohexyl group.

Examples of the divalent saturated hydrocarbon group of L ⁵¹ are a divalent aliphatic saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent aliphatic saturated hydrocarbon group is preferable.

Examples of the divalent aliphatic saturated hydrocarbon group include an alkanediyl group, such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group and a pentanediyl group.

The divalent alicyclic saturated hydrocarbon group includes any of a monocyclic group and a polycyclic group. Examples of the monocyclic alicyclic saturated hydrocarbon group include a cycloalkanediyl group, such as a cyclopentanediyl group and a cyclohexanediyl group. Examples of the polycyclic saturated hydrocarbon group include an adamantanediyl group and a norbornanediyl group.

Examples of the group in which the methylene group contained in the saturated hydrocarbon group is substituted with an oxygen atom or a carbonyl group includes groups represented by formulas (L1-1) to (L1-4). In formulas (L1-1) to (L1-4), * represents a bond with an oxygen atom.

Here, X ^x1 represents a carbonyloxy group or an oxycarbonyl group,

L ^x1 represents a C ₁ to C ₁₆ divalent aliphatic saturated hydrocarbon group,

L ^x2 represents a single bond or a divalent saturated hydrocarbon group of C ₁ to C ₁₅ ,

However, the sum total of the total number of carbons contained in the group of L ^x1 and L ^x2 is 16 or less.

L ^x3 represents a single bond or a divalent aliphatic saturated hydrocarbon group of C ₁ to C ₁₇ ,

L ^x4 represents a single bond or a divalent saturated hydrocarbon group of C ₁ to C ₁₆ ,

However, the total of the total number of carbons contained in the group of L ^x3 and L ^x4 is 17 or less.

L ^x5 represents a C ₁ to C ₁₅ divalent aliphatic saturated hydrocarbon group,

L ^x6 and L ^x7 are each independently a single bond or a C ₁ to C ₁₄ divalent saturated hydrocarbon group,

However, the total of the total number of carbons contained in the group of L ^x5 , L ^x6 and L ^x7 is 15 or less.

L ^x8 and L ^x9 are each independently a single bond or a C ₁ to C ₁₂ divalent saturated hydrocarbon group,

W ^x1 represents a divalent alicyclic saturated hydrocarbon group of C ₃ to C ₁₅ ,

However, the total of the total number of carbons contained in the group of L ^x8 , L ^x9 and W ^x1 is 15 or less.

L ^x1 is preferably a C ₁ to C ₈ divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.

L ^x2 is preferably a single bond or a C ₁ to C ₈ divalent aliphatic saturated hydrocarbon group, more preferably a single bond.

L ^x3 is preferably a C ₁ to C ₈ divalent aliphatic saturated hydrocarbon group.

L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group of C ₁ to C ₈ .

L ^x5 is preferably a C ₁ to C ₈ divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.

L ^x6 is preferably a single bond or a C ₁ to C ₈ divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.

L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group of C ₁ to C ₈ .

L ^x8 is preferably a single bond or a C ₁ to C ₈ divalent aliphatic saturated hydrocarbon group, more preferably a single bond or a methylene group.

L ^x9 is preferably a single bond or a C ₁ to C ₈ divalent aliphatic saturated hydrocarbon group, more preferably a single bond or a methylene group.

W ^x1 is preferably a C ₃ to C ₁₀ divalent alicyclic saturated hydrocarbon group, more preferably a cyclohexanediyl group or an adamantanediyl group.

Examples of the group represented by formula (L1-1) include the following.

Examples of the group represented by the formula (L1-2) include the following.

Examples of the group represented by formula (L1-3) include the following.

Examples of the group represented by formula (L1-4) include the following.

L ⁵¹ is preferably a single bond, a methylene group, an ethylene group, or a group represented by the formula (L1-1), and more preferably a single bond or a group represented by the formula (L1-1).

Examples of the structural unit (a5-1) include the following.

When the resin (A) has the structural unit (a5), the content is usually 1 to 30 mol%, preferably 2 to the total (100 mol%) of all structural units of the resin (A). to 20 mol%, more preferably 3 to 15 mol%.

Resin (A) may further contain well-known structural units other than said structural unit.

The resin (A) is preferably a resin having a structural unit (a1) and a structural unit (s), that is, a copolymer of a monomer (a1) and a monomer (s). In the copolymer, the structural unit (a1) is preferably at least one of the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group). and more preferably at least two of the structural unit (a1-1) or the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group). .

The structural unit (s) is preferably at least one of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably a structural unit represented by formula (a2-1).

The structural unit (a3) is preferably a structural unit represented by a formula (a3-1-1) to a formula (a3-1-4), a formula (a3-2-1) to a formula (a3-2-4) It is at least 1 sort(s) of the structural unit represented by the structural unit and formula (a3-4-1) - the structural unit represented by a formula (a3-4-2).

In the resin (A), the content of the structural unit derived from the monomer having an adamantyl group (in particular, the structural unit (a1-1)) is preferably 15 mol% or more with respect to the structural unit (a1). As the molar ratio of the structural unit derived from the monomer having an adamantyl group increases within this region, the dry etching resistance of the obtained resist improves.

The resin (A) can be prepared by a known polymerization method, for example, a radical polymerization method, using one or more species of the above monomers. The content rate of the structural unit in the resin (A) can be adjusted by changing the amount of the monomer used for polymerization.

The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, more preferably 3,000 or more), and 50,000 or less (more preferably 30,000 or less, more preferably 15,000 or less).

The weight average molecular weight is a value measured by gel permeation chromatography using polystyrene as a standard product. The detailed conditions of this assay are described in the Examples.

< Resin other than Resin (A) >

The resist composition of the present invention may further contain a resin other than the resin (A). Examples of the resin include a resin having only the structural unit (S).

The resin other than the resin (A) is preferably a resin comprising the structural unit (a4) (which is sometimes referred to as “resin (X)”). In the resin (X), the content of the structural unit (a4) is preferably 40 mol% or more, more preferably 45 mol%, with respect to the total (100 mol%) of all structural units constituting the resin (X). % or more, and more preferably 50 mol% or more.

Examples of the structural unit that the resin (X) may further include include the structural unit (a2), the structural unit (a3), and the structural unit derived from a known monomer.

The weight average molecular weight of the resin (X) is preferably 8,000 or more (more preferably 10,000 or more) and 80,000 or less (more preferably 60,000 or less). The method of measuring the weight average molecular weight of resin (X) is the same as that in the case of resin (A).

When the resist composition contains the resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, more preferably 1 to 50 parts by mass, based on the resin (A) (100 parts by mass). Preferably it is 1-40 mass parts, Especially preferably, it is 2-30 mass parts.

The total content of the resin (A) and the resin other than the resin (A) is preferably 80 mass% to 99 mass%, more preferably 90 mass% to 99 mass%, based on the total amount of solid content of the resist composition. to be.

The solid content content of the resist composition and the resin content of the solid content can be measured by known analytical methods such as liquid chromatography and gas chromatography.

<Acid generator (B)>

The acid generator (B) may be an ionic acid generator or a nonionic generator. Ionic acid generators are preferred. Examples of the ionic acid generator include an ionic acid generator composed of a combination of a known cation and a known anion.

Examples of the acid generator (B) include organic sulfonic acid organic sulfonium salts, and are described in Japanese Patent Application Laid-Open No. 2013-68914, Japanese Patent Application Laid-Open No. 2013-3155, and Japanese Patent Application Laid-Open No. 2013-11905. An acid generator is included, and the salt specifically represented by a formula (B1-1) - a formula (B1-30) is included.

Among them, a salt containing an arylsulfonium cation is preferable, and a formula (B1-1), a formula (B1-2), a formula (B1-3), a formula (B1-6), a formula (B1-7), Formula (B1-11), Formula (B1-12), Formula (B1-13), Formula (B1-14), Formula (B1-20), Formula (B1-21), Formula (B1-22), Formula (B1-23), a salt represented by a formula (B1-24), a formula (B1-25), a formula (B1-26), or a formula (B1-29) is more preferable.

In the resist composition, the content of the salt (a) is preferably 0.1 mass% to 35 mass%, more preferably 0.5 mass% to 30 mass%, and more preferably 0.1 mass% to 35 mass% with respect to the total amount of solid content of the resist composition. It is preferably from 1% by mass to 25% by mass.

When the resist composition contains the acid generator (B) together with the salt (a), the total content of the salt (a) and the acid generator (B) is preferably 100% by mass of the resin (A). 1.5 mass % or more (more preferably 3 mass % or more), Preferably it is 40 mass % or less (more preferably 35 mass % or less).

The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably) with respect to 100 parts by mass of the resin (A). 25 parts by mass or less). The resist composition of the present invention may contain, in addition to the salt (a), a single acid generator (B), or a combination of two or more acid generators (B).

The content ratio of the salt (a) and the acid generator (B) (salt (a)/acid generator (B), which is a mass ratio) is usually 1/99 to 100/0, preferably 1/99 to 99/ 1, More preferably, 2/98-98/2, More preferably, 5/95-95/5 may be sufficient.

< Solvent (E) >

The content rate of the solvent (E) is 90 mass % or more, Preferably it is 92 mass % or more, More preferably, it is 94 mass % or more, More preferably, it is 99 mass % or less, More preferably, it is 99.9 mass %. is below. The content of the solvent (E) can be measured, for example, by a known analysis method such as liquid chromatography or gas chromatography.

Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; and cyclic esters such as γ-butyrolactone. These solvents (E) can be used as a single solvent or as a mixture of two or more solvents.

< ??

The resist composition of the present invention may contain a substance such as a basic nitrogen-containing organic compound or a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.

The content rate of the oxidizing agent is preferably 0.01 to 5 mass % with respect to the total amount of solid content of the resist composition.

Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. The amine may be an aliphatic amine or an aromatic amine. The aliphatic amine includes any one of a primary amine, a secondary amine, and a tertiary amine.

Specific examples of amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, Triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Dihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, Ethyldioctylamine, ethyldinonylamine, ethyl didecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylene Diamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-di Ethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane, 1,2-di( 4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2- Di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2 ,2'-dipicolylamine, bipyridine. Among these, diisopropyl aniline is preferable, and 2,6-diisopropyl aniline is especially more preferable.

Specific examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammoniumhydroxide, tetra-n-butylammoniumsalicylate and choline.

< Weak acid salt (D) >

The weak acid salt (D) is a salt that generates an acid having a weaker acidity than the acid generated from the salt (a) and the acid generator (B). "Acidity" can be expressed in terms of the acid dissociation constant, pKa, of an acid produced from a weak acid salt. Examples of the weak acid salt (D) include salts which generate acids whose pKa is usually -3 or more, preferably -1 to 7, more preferably 0 to 5.

Specific examples of weak acid salts include the following salts, weak acid intramolecular salts of formula (D), and Japanese Patent Laid-Open No. 2012-229206, Japanese Patent Application Laid-Open No. 2012-6908, and Japanese Patent Application Laid-Open No. 2012-72109 The salt of Unexamined-Japanese-Patent No. 2011-39502 and Unexamined-Japanese-Patent No. 2011-191745 is included, Preferably the salt of a formula (D) is included.

Here, R ^D1 and R ^D2 are, in each case, each independently a C ₁ to C ₁₂ hydrocarbon group, a C ₁ to C ₆ alkoxy group, a C ₂ to C ₇ acyl group, and C ₂ to C ₇ represents an acyloxy group, a C ₂ to C ₇ alkoxycarbonyl group, a nitro group or a halogen atom, and

m' and n' each independently represent the integer of 0-4.

The hydrocarbon group of R ^D1 and R ^D2 includes any of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and combinations thereof.

Examples of the aliphatic hydrocarbon group include an alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, and a nonyl group.

The alicyclic hydrocarbon group is any one of a monocyclic or polycyclic hydrocarbon group and a saturated or unsaturated hydrocarbon group. Examples thereof include a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclononyl group, and a cyclododecyl group; an adamantyl group and a norbornyl group. The alicyclic hydrocarbon group is preferably a saturated hydrocarbon group.

Examples of the aromatic hydrocarbon group include a phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-tert-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, and aryl groups such as a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group.

Examples of these combined groups include an alkyl-cycloalkyl group, a cycloalkyl-alkyl group, an aralkyl group (eg, phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1-propyl group, 1- Phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group practice) is included.

Examples of the alkoxy group include a methoxy group and an ethoxy group.

Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group.

Examples of the acyloxy group include a group in which an oxy group (-O-) is bonded to the acyl group.

Examples of the alkoxycarbonyl group include a group in which a carbonyl group (-CO-) is bonded to the alkoxy group.

Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom.

In Formula (D), R ^D1 and R ^D2 in each case are each independently a C ₁ to C ₈ alkyl group, C ₃ to C ₁₀ cycloalkyl group, C ₁ to C ₆ alkoxy group, C ₂ to Represents a C ₄ acyl group, a C ₂ to C ₄ acyloxy group, a C ₂ to C ₄ alkoxycarbonyl group, a nitro group or a halogen atom.

m' and n' are each independently preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and still more preferably 0.

Specific examples of the salt in the weak acid molecule include the following.

The weak acid intramolecular salt of formula (D) can be prepared by the method described in "Tetrahedron Vol.45, No.19, p 6281-6296". In addition, a commercially available compound can be used as the compound (D).

In the resist composition of the present invention, the content of a salt that generates an acid with a weaker acidity than the acid generated from the acid generator, for example, salt (D) in the weak acid molecule, is based on the total amount of solid content of the resist composition; Preferably it is 0.01-5 mass %, More preferably, it is 0.01-4 mass %, More preferably, it is 0.01-3 mass %.

< Other ingredients >

In addition, the resist composition may include other components (which are sometimes referred to as "other components (F)"). The other component (F) contains various additives such as a sensitizer, a dissolution inhibitor, a surfactant, a stabilizer, and a dye, if necessary.

<Preparation of resist composition>

The resist composition of the present invention may contain, if necessary, the resin (A), the salt (a) of the present invention, the acid generator (B), and a resin other than the resin (A), a compound, a weak acid intramolecular salt ( It can prepare by mixing D), a solvent (E), and another component (F). It does not specifically limit in the mixing order. Mixing may be performed in any order. The mixing temperature may be adjusted to an appropriate temperature in the range of 10 to 40° C. according to the type of resin or the solubility of the resin in the solvent (E). The mixing time may be adjusted to an appropriate time in the range of 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited. Agitated mixing may be employed.

After mixing the above components, the resist composition of the present application can be prepared by filtering the mixture through a filter having a pore diameter of approximately 0.003 to 0.2 mu m.

<Method for producing resist pattern>

The method for producing the resist pattern of the present invention comprises:

(1) a step of applying the resist composition of the present invention on a substrate;

(2) drying the applied composition to form a composition layer;

(3) a step of exposing the composition layer;

(4) heating the exposed composition layer; and

(5) The process of developing the heated composition layer is included.

Application of the resist composition onto the substrate can be carried out using a resist coating apparatus, such as a spin coater, which is typically known in the art of semiconductor microfabrication. Examples of the substrate include an inorganic substrate, such as a silicon wafer. Before apply|coating a resist composition, a board|substrate may be wash|cleaned, and you may form an organic antireflection film on a board|substrate using a commercially available antireflection composition.

The solvent is evaporated from the resist composition, and a composition layer from which the solvent is removed is formed. Drying of the applied composition layer can be done, for example, using a heating device, such as a hot plate (so-called prebaking), or using a pressure reducing device or a combination thereof. Heating temperature becomes like this. Preferably it is within the range of 50-200 degreeC. The heating time is preferably 10 to 180 seconds. The pressure of the reduced pressure is preferably within the range of 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is exposed using an exposure machine or an immersion exposure machine normally. The exposure is performed by a laser in the ultraviolet region, for example, KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm) radiation, solid-state laser light source (YAG or semiconductor laser, etc.) ) by wavelength-converting the laser light from the wavelength-converted laser beam, radiation of a harmonic laser beam in a far-ultraviolet region or vacuum ultraviolet region, or radiation of an electron beam or EUV, etc., is usually carried out using various types of exposure machines. In this specification, irradiating these radiations is sometimes collectively referred to as exposure. Exposure is usually performed through a mask corresponding to a required pattern. When an electron beam is used as the exposure light source, it can be done by direct drawing without use of a mask.

After exposure, the composition layer is subjected to a heat treatment (so-called post-exposure bake) in order to accelerate the deprotection reaction. The heat treatment may be performed using a heating device such as a hot plate. Heating temperature is the range of 50-200 degreeC normally, Preferably it is the range of 70-150 degreeC.

Developing the heated composition layer is normally performed with a developing solution using a developing apparatus. Developing can be performed in the manner of a dip method, a puddle method, a spray method, or a dynamic dispensing method. Development temperature is 5-60 degreeC normally. The development time is usually 5 to 300 seconds.

The photoresist pattern obtained from the photoresist composition may be positive or negative depending on the choice of a suitable developer.

Development for obtaining a positive photoresist pattern is usually performed with an alkaline developer. The alkaline developer used may be any of various alkaline aqueous solutions used in this field. Usually, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly referred to as choline) is frequently used. Surfactant may be contained in alkaline developing solution.

After development, the formed resist pattern is preferably washed with ultrapure water, and the residue left on the resist layer or on the substrate is preferably removed.

Development for obtaining a negative photoresist pattern is usually performed with a developer containing an organic solvent. The organic solvent used may be any of various organic solvents used in this field, and examples of these include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents, such as N,N-dimethylacetamide; Contains aromatic hydrocarbon solvents such as anisole.

In the developer containing the organic solvent, the amount of the organic solvent in the developer is preferably 90% by mass to 100% by mass, more preferably 95% by mass to 100% by mass. The developer more preferably consists essentially of an organic solvent.

Especially, the developing solution containing an organic solvent, Preferably butyl acetate and/or 2-heptanone are included. In the developer containing the organic solvent, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass in the developer, more preferably 90% by mass to 100% by mass in the developer. The developer more preferably consists essentially of butyl acetate and/or 2-heptanone.

The developing solution containing an organic solvent may contain surfactant. Moreover, the developing solution containing an organic solvent may also contain a trace amount of water|moisture content.

Developing with the developing solution containing an organic solvent can be complete|finished by substituting a developing solution with another solvent.

After development, the formed photoresist pattern is preferably washed with a rinsing solution. The rinsing solution is not limited as long as it does not damage the photoresist pattern. Examples of the rinsing solution include a solvent containing an organic solvent other than the above developer, such as an alcohol solvent or an ester solvent.

After cleaning, the residual rinse liquid left on the substrate or photoresist layer is preferably removed.

< Use >

The resist composition of the present invention is preferably useful for excimer laser lithography, such as lithography for KrF, ArF, electron beam (EB) exposure, or lithography for ultra-ultraviolet light (EUV) exposure, more preferably for electron beam (EB) exposure It is useful for lithography of , lithography for ArF excimer laser exposure, and lithography for ultra-ultraviolet light (EUV) exposure.

The resist composition of the present invention can be used in semiconductor microfabrication.

Examples

All percentages and parts expressing the content or amount used in Examples and Comparative Examples are based on mass unless otherwise specified.

The weight average molecular weight is a value measured by gel permeation chromatography.

Column: TSKgel Multipore HXL-M x 3+guardcolumn (manufactured by Tosoh)

Eluent: tetrahydrofuran

Flow rate: 1.0 mL/min

Detector: RI Detector

Column temperature: 40℃

Injection volume: 100 μl

Standard material for calculating molecular weight: standard polystyrene (manufactured by Tosoh Corporation)

The structure of the compound was measured by mass spectrometry (liquid chromatography: type 1100, manufactured by Agilent, mass spectrometry: LC/MSD type, manufactured by Agilent). The peak value in mass spectrometry is referred to as “MASS”.

Example 1: Synthesis of salt represented by formula (I-1)

The salt represented by Formula (I-1-a) is synthesize|combined by the method of Unexamined-Japanese-Patent No. 2007-224008.

In a reactor, 7.00 parts of the salt represented by the formula (I-1-a), 6.50 parts of the compound represented by the formula (I-1-b), 35 parts of chloroform, 14 parts of acetonitrile and 14 parts of dimethylformamide are put; The mixture was stirred at 23° C. for about 30 minutes. Then, 0.07 parts of p-toluenesulfonic acid was added, and the obtained solution was heated and refluxed and stirred for 3 hours. The obtained reaction product was cooled to 23° C., 155 parts of chloroform was added, and the resulting mixture was stirred and filtered. To the resulting filtrate, 40 parts of a 5% aqueous sodium hydrogen carbonate solution was added, and the resulting mixture was stirred at 23°C for 30 minutes. After that, the mixture was allowed to stand and the organic layer was separated. 45 parts of ion-exchanged water is added to the obtained organic layer, and the obtained mixture is stirred at 23 degreeC for 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 3 times. After adding 95 parts of ethyl acetate to the obtained organic layer, and stirring the obtained mixture, the supernatant liquid was removed. The obtained residue is dissolved in acetonitrile. Thereafter, the mixture was concentrated to obtain 4.38 parts of a salt represented by the formula (I-1-c).

In a reactor, 2.20 parts of the compound represented by formula (I-1-d) and 8.82 parts of acetonitrile were put, and the mixture was stirred at 23°C for about 30 minutes. Then, 1.88 parts of the salt represented by Formula (I-1-e) was added over 15 minutes, and it stirred at 50 degreeC for 1 hour. To the obtained reaction product, 2.00 parts of a salt represented by formula (I-1-c) was added, and the resulting mixture was stirred at 50°C for 10 hours. The obtained reaction product was cooled to 23°C, 110 parts of chloroform and 35 parts of ion-exchanged water were added, and the resulting mixture was stirred and left still to separate the organic layer. To the obtained organic layer, 35 parts of ion-exchanged water is added, and the organic layer is separated and washed with water. This washing operation was performed 7 times. The obtained organic layer was concentrated, and 3 parts of acetonitrile, 16 parts of ethyl acetate, and 16 parts of t-butylmethyl ether were added to the obtained residue, and the obtained mixture was stirred at 23 degreeC for about 30 minutes, and the supernatant liquid was removed. Then, 1.45 parts of salts represented by Formula (I-1) were obtained by concentrating the residue.

MS(ESI(+)Spectrum) : M ⁺ 263.1

MS(ESI(-)Spectrum) : M ^- 793.3

Example 2: Synthesis of salt represented by formula (I-2)

In a reactor, 4.12 parts of the compound represented by formula (I-2-d) and 42 parts of acetonitrile were put, and the mixture was stirred at 23°C for about 30 minutes. Thereafter, 3.51 parts of the compound represented by the formula (I-1-e) was added to the obtained solution over 15 minutes, and the resulting mixture was stirred at 60°C for 1 hour. To the obtained reaction product, 3.74 parts of a salt represented by formula (I-1-c) was added, and the resulting mixture was stirred at 60° C. for about 48 hours. The obtained reaction product was cooled to 23° C., 100 parts of chloroform and 30 parts of ion-exchanged water were added, and the resulting mixture was stirred. Thereafter, the mixture was allowed to stand and the organic layer was separated. To the separated organic layer, 30 parts of ion-exchanged water is added, and the resulting mixture is stirred at 23° C. for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 7 times. The obtained organic layer was concentrated, and 6 parts of acetonitrile, 25 parts of ethyl acetate, and 25 parts of t-butylmethyl ether were added to the obtained residue, and the obtained mixture was stirred at 23 degreeC for about 30 minutes, and the supernatant liquid was removed. After that, the residue was concentrated to obtain 2.48 parts of the salt represented by the formula (I-2).

MS(ESI(+)Spectrum) : M ⁺ 263.1

MS(ESI(-)Spectrum) : M ^- 797.3

Example 3: Synthesis of salt represented by formula (I-3)

In a reactor, 3.82 parts of the compound represented by formula (I-3-d) and 38 parts of acetonitrile are put, and the resulting mixture is stirred at 23°C for about 30 minutes. 3.51 parts of the compound represented by the formula (I-1-e) was added to the resulting solution over 15 minutes, and the resulting mixture was stirred at 60°C for 1 hour. To the obtained reaction product, 3.74 parts of a salt represented by formula (I-1-c) was added, and the resulting mixture was stirred at 60° C. for about 48 hours. The obtained reaction product was cooled to 23° C., 100 parts of chloroform and 30 parts of ion-exchanged water were added, and the resulting mixture was stirred. Thereafter, the mixture was allowed to stand and the organic layer was separated. 30 parts of ion-exchanged water is added to the obtained organic layer, and the obtained mixture is stirred at 23 degreeC for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 7 times. The resulting organic layer was concentrated, and 6 parts of acetonitrile and 25 parts of t-butylmethyl ether were added to the resulting residue, and the resulting mixture was stirred at 23° C. for about 30 minutes, and then the supernatant was removed. Then, 4.57 parts of salts represented by Formula (I-3) were obtained by concentrating the obtained residue.

MS(ESI(+)Spectrum) : M ⁺ 263.1

MS(ESI(-)Spectrum) : M ^- 765.3

Example 4: Synthesis of salt represented by formula (I-4)

The salt represented by Formula (I-4-a) was synthesize|combined by the method of Unexamined-Japanese-Patent No. 2012-224611.

In a reactor, 10 parts of the salt represented by the formula (I-4-a), 9.71 parts of the compound represented by the formula (I-1-b) and 100 parts of dimethylformamide were put, and the mixture was stirred at 23° C. for about 30 minutes. Then, 0.10 parts of p-toluenesulfonic acid was added to the obtained solution, and the obtained solution was heated and refluxed and stirred for 3 hours. The obtained reaction material was cooled to 23 degreeC, 240 parts of chloroform was added, and the obtained mixture was stirred and filtered. To the resulting filtrate, 40 parts of a 5% aqueous sodium hydrogen carbonate solution was added, and the resulting mixture was stirred at 23°C for 30 minutes. Thereafter, the mixture was allowed to stand and the organic layer was separated. To the obtained organic layer, 70 parts of ion-exchanged water is added, the resulting mixture is stirred at 23°C for 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 3 times. By concentrating the obtained organic layer, 6.33 parts of a salt represented by Formula (I-4-c) was obtained.

In a reactor, 2.20 parts of the compound represented by formula (I-1-d) and 8.82 parts of acetonitrile were put, and the mixture was stirred at 23°C for about 30 minutes. Thereafter, 1.88 parts of the compound represented by the formula (I-1-e) was added to the obtained solution over 15 minutes, and the resulting mixture was stirred at 50°C for 1 hour. To the obtained reaction product, 1.93 parts of a salt represented by formula (I-4-c) was added, and the resulting mixture was stirred at 50°C for 10 hours. The obtained reaction product was cooled to 23°C, 100 parts of chloroform and 35 parts of ion-exchanged water were added, and the resulting mixture was stirred and left still to separate the organic layer. 35 parts of ion-exchanged water is added to the obtained organic layer, and it stirs at 23 degreeC for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 5 times. The obtained organic layer was concentrated, and 3 parts of acetonitrile, 20 parts of ethyl acetate, and 20 parts of t-butylmethyl ether were added to the obtained residue, and the obtained mixture was stirred at 23 degreeC for about 30 minutes, and the supernatant liquid was removed. Then, 1.38 parts of salts represented by Formula (I-4) were obtained by concentrating the obtained residue.

MS(ESI(+)Spectrum) : M ⁺ 237.1

MS(ESI(-)Spectrum) : M ^- 793.3

Example 5: Synthesis of salt represented by formula (I-5)

In a reactor, 13.04 parts of the compound represented by the formula (I-5-a), 15.22 parts of the compound represented by the formula (I-5-b) and 200 parts of chloroform were put, and the mixture was stirred at 23° C. for about 30 minutes. To the obtained mixture, 0.61 part of sulfuric acid was added, and the obtained solution was heated and refluxed at 60°C for 12 hours in the presence of a molecular sieve. The obtained reaction mass was cooled to 23°C, 65 parts of a 10% aqueous potassium carbonate solution were added, and the resulting mixture was stirred at 23°C for 30 minutes. Then, the obtained mixture was left still, and the organic layer was liquid-separated. To the obtained organic layer, 80 parts of ion-exchanged water is added, the resulting mixture is stirred at 23°C for 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 4 times. The washed organic layer is concentrated. To the obtained residue, 25 parts of methanol and 25 parts of ion-exchanged water were added, and the resulting mixture was stirred at 23°C for 30 minutes and filtered to obtain 12.93 parts of a compound represented by formula (I-5-c).

In a reactor, 12.93 parts of a compound represented by formula (I-5-c) and 65 parts of acetone were added, and the mixture was stirred at 0°C for 30 minutes. To the obtained mixture, 44 parts of 5% sodium hydroxide aqueous solution was added, and the obtained solution was stirred at 23 degreeC for 18 hours. 280 parts of 5% aqueous oxalic acid solution and 250 parts of ethyl acetate were added to the obtained reaction material, and it stirred at 23 degreeC for 30 minutes. Then, the obtained mixture was left still, and the organic layer was liquid-separated. 150 parts of ion-exchanged water is added to the obtained organic layer, the obtained mixture is stirred at 23 degreeC for 30 minute(s), the organic layer is liquid-separated and it washes with water. This washing operation was performed 3 times. The washed organic layer was concentrated. To the obtained residue, 50 parts of n-heptane was added, and the mixture was stirred at 23°C for 30 minutes and filtered to obtain 9.54 parts of a compound represented by the formula (I-5-d).

In a reactor, 8.65 parts of the compound represented by formula (I-5-d) and 34.60 parts of acetonitrile are put, and the mixture is stirred at 23°C for about 30 minutes. Thereafter, 4.23 parts of the compound represented by the formula (I-1-e) was added to the obtained solution over 15 minutes, and the resulting mixture was stirred at 50°C for 1 hour. 6.00 parts of the compound represented by Formula (I-1-c) was added to the obtained reaction material over 15 minutes, and the obtained mixture was stirred at 50 degreeC for 18 hours. The obtained reaction product was cooled to 23°C, 100 parts of chloroform and 35 parts of ion-exchanged water were added, and the resulting mixture was stirred and left still to separate the organic layer. 35 parts of ion-exchanged water is added to the obtained organic layer, stirred at 23 degreeC for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 5 times. The obtained organic layer is concentrated, and 3 parts of acetonitrile, 20 parts of ethyl acetate, and 100 parts of t-butylmethyl ether are added to the obtained residue, and the obtained mixture is stirred at 23 degreeC for about 30 minutes, and the supernatant liquid is removed. Then, 2.09 parts of salts represented by Formula (I-5) were obtained by concentrating the obtained residue.

MS(ESI(+)Spectrum) : M ⁺ 263.1

MS(ESI(-)Spectrum) : M ^- 1081.3

Example 6: Synthesis of salt represented by formula (I-6)

In a reactor, 50 parts of the compound represented by the formula (I-6-a), 10.33 parts of the compound represented by the formula (I-6-b) and 350 parts of chloroform were put, and the mixture was stirred at 23° C. for about 30 minutes. To the obtained mixture, 0.20 part of copper (II) acetate was added, and the obtained solution was heated, refluxed at 80 degreeC for 2 hours, and it concentrated. To the obtained concentrate, 440 parts of tert-butylmethyl ether was added, and the obtained mixture was stirred and filtered to obtain 32.96 parts of a salt represented by the formula (I-6-c).

To 10 parts of tetrahydrofuran, at 5°C, 2.21 parts of lithium aluminum hydride were added, and the resulting mixture was stirred at 5°C for about 30 minutes. Thereafter, 8.22 parts of the salt represented by the formula (I-6-d) and 30 parts of tetrahydrofuran were added to the resulting solution over 1 hour, and the resulting mixture was stirred at 23°C for 18 hours. 30 parts of 1N hydrochloric acid was added to the obtained reaction material, and it concentrated. To the resulting concentrate, 82 parts of acetonitrile was added, and the resulting mixture was stirred and filtered. By concentrating the obtained filtrate, 6.28 parts of a compound represented by Formula (I-6-e) was obtained.

13.25 parts of the compound represented by Formula (I-6-f) and 40 parts of acetonitrile were put, and it stirred at 23 degreeC for about 30 minutes. To the obtained solution, 11.63 parts of a compound represented by formula (I-1-e) was added, and the resulting mixture was stirred at 40°C for 1 hour. To the obtained reaction product, a mixed solution of 6.28 parts of a salt represented by formula (I-6-h) and 13.20 parts of acetonitrile was added, and the resulting mixture was stirred at 23° C. for 16 hours. 30 parts of acetonitrile was added to the obtained reaction material, and it filtered. By concentrating the obtained filtrate, 9.06 parts of a compound represented by Formula (I-6-i) was obtained.

In the reactor, 9.06 parts of the salt represented by the formula (I-6-i), 11.89 parts of the salt represented by the formula (I-6-c), 20 parts of acetonitrile, 63 parts of chloroform and 31.44 parts of a 5% aqueous oxalic acid solution are added and stirred at 23° C. for about 30 minutes, and left still to separate the organic phase. Thereafter, 21 parts of a 5% aqueous oxalic acid solution is added to the separated layer and stirred at 23° C. for about 30 minutes to separate the organic layer. This washing operation was repeated 3 times. To the obtained organic layer, 21 parts of a 5% aqueous sodium hydrogen carbonate solution is added, stirred at 23° C. for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was repeated twice. 21 parts of ion-exchanged water is added to the obtained organic layer, and the mixture is stirred at 23° C. for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was repeated 3 times. The obtained organic layer was concentrated. To the obtained residue, 80 parts of acetonitrile and 60 parts of ethyl acetate were added and filtered to obtain 4.53 parts of a compound represented by the formula (I-6-j).

In a reactor, 10.25 parts of the salt represented by the formula (I-6-j), 9.71 parts of the compound represented by the formula (I-1-b) and 100 parts of dimethylformamide were put, and the mixture was stirred at 23° C. for about 30 minutes. Then, 0.10 parts of p-toluenesulfonic acid was added to the obtained solution, and the obtained solution was heated and refluxed and stirred for 3 hours. The obtained reaction material was cooled to 23 degreeC, 250 parts of chloroform was added, and the obtained mixture was stirred and filtered. To the resulting filtrate, 40 parts of a 5% aqueous sodium hydrogen carbonate solution was added, and the resulting mixture was stirred at 23°C for 30 minutes. Then, the obtained mixture was left still, and the organic layer was liquid-separated. To the obtained organic layer, 70 parts of ion-exchanged water is added, the resulting mixture is stirred at 23°C for 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 3 times. By concentrating the obtained organic layer, 6.38 parts of salt represented by Formula (I-6-1) was obtained.

2.20 parts of the compound represented by Formula (I-1-d) and 8.82 parts of acetonitrile were put, and it stirred at 23 degreeC for about 30 minutes. Thereafter, 1.88 parts of the compound represented by the formula (I-1-e) was added to the obtained solution over 15 minutes, and the resulting mixture was stirred at 50°C for 1 hour. To the obtained reaction product, 1.93 parts of a salt represented by formula (I-6-1) was added, and the resulting mixture was stirred at 50°C for 10 hours. The obtained reaction product was cooled to 23°C, 100 parts of chloroform and 35 parts of ion-exchanged water were added, and the resulting mixture was stirred and left still to separate the organic layer. 35 parts of ion-exchanged water is added to the obtained organic layer, and it stirs at 23 degreeC for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 5 times. The obtained organic layer was concentrated, and to the obtained residue, 3 parts of acetonitrile, 20 parts of ethyl acetate, and 50 parts of t-butylmethyl ether were added, and the resulting mixture was stirred at 23°C for about 30 minutes, and the supernatant was removed. Then, 1.25 parts of the salt represented by Formula (I-6) was obtained by concentrating the obtained residue.

MS(ESI(+)Spectrum) : M ⁺ 237.1

MS(ESI(-)Spectrum) : M ^- 807.3

Example 7: Synthesis of salt represented by formula (I-7)

In a reactor, 8.65 parts of the compound represented by formula (I-5-d) and 34.60 parts of acetonitrile were put, and the mixture was stirred at 23° C. for about 30 minutes. Thereafter, 4.23 parts of the compound represented by the formula (I-1-e) was added to the obtained solution over 15 minutes, and the resulting mixture was stirred at 50°C for 1 hour. To the reaction product, 5.783 parts of a compound represented by formula (I-4-c) was added over 15 minutes, and the resulting mixture was stirred at 50° C. for 18 hours. The reaction product was cooled to 23° C., 100 parts of chloroform and 35 parts of ion-exchanged water were added, and the resulting mixture was stirred and allowed to stand, and the organic layer was separated. 35 parts of ion-exchanged water is added to the obtained organic layer, and it stirs at 23 degreeC for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 5 times. The obtained organic layer was concentrated, and 20 parts of acetonitrile and 20 parts of t-butylmethyl ether were added to the obtained residue, and it stirred at 23 degreeC for about 30 minutes, and the supernatant liquid was removed. Then, 1.96 parts of salts represented by Formula (I-7) were obtained by concentrating the said residue.

MS(ESI(+)Spectrum) : M ⁺ 237.1

MS(ESI(-)Spectrum) : M ^- 1081.3

Example 8: Synthesis of salt represented by formula (I-8)

The salt represented by Formula (I-8-a) was synthesize|combined by the method of Unexamined-Japanese-Patent No. 2012-224611.

In a reactor, 10.00 parts of the salt represented by the formula (I-8-a), 6.57 parts of the compound represented by the formula (I-8-b) and 100 parts of chloroform were put, and the mixture was stirred at 23° C. for about 30 minutes. Then, 0.10 parts of p-toluenesulfonic acid was added to the obtained solution, and the obtained solution was heated and refluxed and stirred for 3 hours. The obtained reaction product was cooled to 23° C., 240 parts of chloroform were added, and the resulting mixture was stirred and filtered. To the obtained filtrate, 45 parts of a 5% aqueous sodium hydrogencarbonate solution was added, and the resulting mixture was stirred at 23°C for 30 minutes. Thereafter, the mixture was allowed to stand and the organic layer was separated. To the obtained organic layer, 70 parts of ion-exchanged water is added, and the resulting mixture is stirred at 23° C. for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 3 times. By concentrating the obtained organic layer, 11.01 parts of salts represented by Formula (I-8-c) were obtained.

In a reactor, 2.20 parts of the compound represented by formula (I-1-d) and 8.82 parts of acetonitrile were put, and the mixture was stirred at 23°C for about 30 minutes. Thereafter, 1.88 parts of the compound represented by the formula (I-1-e) was added to the obtained solution over 15 minutes, and the resulting mixture was stirred at 50°C for 1 hour. To the obtained reaction product, 3.60 parts of a salt represented by formula (I-8-c) was added, and the resulting mixture was stirred at 50°C for 10 hours. The obtained reaction product was cooled to 23°C, 100 parts of chloroform and 35 parts of ion-exchanged water were added, and the resulting mixture was stirred and left still to separate the organic layer. 35 parts of ion-exchanged water is added to the obtained organic layer, stirred at 23° C. for about 30 minutes, and the organic layer is separated and washed with water. This washing operation was performed 5 times. The organic layer was concentrated, and to the obtained residue, 10 parts of acetonitrile and 120 parts of t-butylmethyl ether were added, and the resulting mixture was stirred at 23° C. for about 30 minutes, and the supernatant was removed. Then, 2.68 parts of salts represented by Formula (I-8) were obtained by concentrating the obtained residue.

MS(ESI(+)Spectrum) : M ⁺ 237.1

MS(ESI(-)Spectrum) : M ^- 573.2

Synthesis Example 1: Synthesis of salt represented by formula (B1-5)

In a reactor, 50.49 parts of the salt represented by Formula (B1-5-a) and 252.44 parts of chloroform were put, and it stirred at 23 degreeC for 30 minutes. Thereafter, 16.27 parts of the compound represented by the formula (B1-5-b) was added dropwise, and the resulting mixture was stirred at 23° C. for 1 hour to obtain a solution containing a salt represented by the formula (B1-5-c). To the obtained solution, 48.80 parts of a salt represented by the formula (B1-5-d) and 84.15 parts of ion-exchanged water were added, and the resulting mixture was stirred at 23°C for 12 hours. From the obtained reaction solution having two phases, the chloroform phase was taken out, and then 84.15 parts of ion-exchanged water was added thereto, followed by washing with water. This washing operation was repeated 5 times. On the washed chloroform, 3.88 parts of activated carbon was added, and the resulting mixture was stirred and filtered. The filtrate taken out was concentrated, 125.87 parts of acetonitrile was added after that, and the obtained mixture was stirred and concentrated. To the obtained residue, 20.62 parts of acetonitrile and 309.30 parts of tert-butylmethyl ether were added, and the mixture was stirred at 23°C for about 30 minutes. Thereafter, the supernatant was removed and the residue was concentrated. To the concentrated residue, 200 parts of n-heptane was added, and the obtained mixture was stirred at 23° C. for about 30 minutes and filtered to obtain 61.54 parts of a salt represented by the formula (B1-5).

MASS(ESI(+)Spectrum) : M ⁺ 375.2

MASS(ESI(-)Spectrum) : M ^- 339.1

Synthesis Example 2: Synthesis of salt represented by formula (B1-21)

The compound represented by the formula (B1-21-b) was produced by the method described in Japanese Patent Laid-Open No. 2008-209917.

In a reactor, 30.00 parts of the compound represented by the formula (B1-21-b), 35.50 parts of the salt represented by the formula (B1-21-a), 100 parts of chloroform and 50 parts of ion-exchanged water are added, and at 23° C., about 15 parts time was stirred. In the obtained reaction mixture having two layers, the chloroform layer was separated. 30 parts of ion-exchanged water was added to the said chloroform layer, and it washed with water. This operation was repeated 5 times. The washed layer is concentrated, and then 100 parts of tert-butylmethyl ether is added to the obtained residue, and the mixture is stirred at 23° C. for about 30 minutes. By filtration of the obtained mixture, 48.57 parts of salts represented by Formula (B1-21-c) were obtained.

In a reactor, 20.00 parts of the salt represented by the formula (B1-21-c), 2.84 parts of the compound represented by the formula (B1-21-d) and 250 parts of monochlorobenzene were put, and the mixture was stirred at 23° C. for 30 minutes. To the obtained mixture, 0.21 part of copper (II) dibenzoate was added, and the obtained mixture was stirred at 100 degreeC for 1 hour. The obtained reaction mixture is concentrated, and then 200 parts of chloroform and 50 parts of ion-exchanged water are added to the obtained residue, and the obtained mixture is stirred at 23 degreeC for 30 minutes, and the organic layer is separated and washed with water. This washing operation was repeated 5 times. 50 parts of ion-exchanged water was added to the obtained organic layer, and the obtained mixture was stirred at 23 degreeC for 30 minutes, and the organic layer was liquid-separated. The obtained organic layer was concentrated, and then the obtained residue was dissolved in 53.51 parts of acetonitrile. Thereafter, the mixture was concentrated, 113.05 parts of tert-butylmethyl ether was added, and the resulting mixture was stirred and filtered to obtain 10.47 parts of a salt represented by the formula (B1-21).

MASS(ESI(+)Spectrum) : M ⁺ 237.1

MASS(ESI(-)Spectrum) : M ^- 339.1

Synthesis Example 3: Synthesis of salt represented by formula (B1-22)

In a reactor, 11.26 parts of the salt represented by the formula (B1-21-a), 10.00 parts of the compound represented by the formula (B1-22-b), 50 parts of chloroform and 25 parts of ion-exchanged water are added, and the reaction temperature is about 15 parts at 23°C. time was stirred. The resulting reaction mixture having two layers was separated from the chloroform layer. 15 parts of ion-exchanged water was added to the said chloroform layer, and it washed with water. This operation was repeated 5 times. Thereafter, the washed layer is concentrated, and to the obtained residue, 50 parts of tert-butylmethyl ether is added, and the resulting mixture is stirred at 23° C. for about 30 minutes. 11.75 parts of salts represented by Formula (B1-22-c) were obtained by filtering the obtained mixture.

In a reactor, 11.71 parts of the salt represented by the formula (B1-22-c), 1.7 parts of the compound represented by the formula (B1-22-d) and 46.84 parts of monochlorobenzene were put, and the mixture was stirred at 23° C. for 30 minutes. To the obtained mixture, 0.12 part of copper (II) dibenzoate was added, and the obtained mixture was stirred at 100 degreeC for 30 minute(s). The reaction mixture is concentrated, and 50 parts of chloroform and 12.5 parts of ion-exchanged water are added to the residue obtained after that, and the resulting mixture is stirred at 23° C. for 30 minutes, and the organic layer is separated and washed with water. 12.50 parts of ion-exchanged water is added to the obtained organic layer, and it stirs at 23 degreeC for 30 minutes, The organic layer is separated and washed with water. This washing operation was repeated 8 times. Thereafter, the mixture was concentrated, 50 parts of tert-butylmethyl ether was added, and the resulting mixture was stirred and filtered to obtain 6.84 parts of a salt represented by the formula (B1-22).

MASS(ESI(+)Spectrum) : M ⁺ 237.1

MASS(ESI(-)Spectrum) : M ^- 323.0

Examples of resin synthesis

The monomers used for the synthesis examples of the resin are shown below. These monomers are referred to as "monomer (X)", where "(X)" is a symbol of the formula indicating the structure of each monomer.

Synthesis Example 4: Synthesis of Resin A1

Monomer (a1-1-3), Monomer (a1-2-9), Monomer (a2-1-3) and Monomer (a3-4-2), Monomer (a1-1-3), Monomer (a1- 2-9), monomer (a2-1-3), and monomer (a3-4-2) are mixed with each other so that the molar ratio of the monomer (a3-4-2) is 45:14:2.5:38.5, and propylene in an amount equal to 1.5 times by mass of the total amount of the monomer Glycol monomethyl ether acetate is added to obtain a solution. To this solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) as initiators were added in amounts of 1 mol% and 3 mol%, respectively, based on the total amount of the monomers, and the reaction mixture was 73 It was heated at ℃ for about 5 hours. Then, the obtained reaction mixture is poured into the liquid mixture of a large amount of methanol and water, and resin is precipitated. The obtained resin is filtered. The obtained resin is dissolved in another propylene glycol monomethyl ether acetate to obtain a solution, and the solution is poured into a large amount of a mixture of methanol and water to precipitate the resin. The obtained resin is filtered. This operation was repeated twice to obtain a copolymer having a weight average molecular weight of about 7600 in a yield of 68%. The said resin which has a structural unit of the following formula is called resin A1.

Synthesis Example 5: Synthesis of Resin A2

Monomer (a1-1-2), monomer (a2-1-1) and monomer (a3-1-1), monomer (a1-1-2), monomer (a2-1-1), monomer (a3- 1-1))) are mixed with each other so that the molar ratio = 50:25:25, and propylene glycol monomethyl ether acetate in an amount equal to 1.5 mass times the total amount of monomers is added to obtain a solution. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) as initiators were added to the solution in an amount of 1 mol% and 3 mol%, respectively, based on the total amount of the monomers, and the reaction mixture was added to 75 It was heated at ℃ for about 5 hours. Then, the obtained reaction mixture is poured into the liquid mixture of a large amount of methanol and water, and resin is precipitated. The obtained resin is filtered. The obtained resin is dissolved in another propylene glycol monomethyl ether acetate to obtain a solution, and the solution is poured into a mixture of methanol and water to precipitate the resin. The obtained resin is filtered. This operation was repeated three times to obtain a copolymer having a weight average molecular weight of about 9100 in a yield of 66%. The said resin which has the structural unit of the following formula is called resin A2.

Synthesis Example 6: Synthesis of Resin X1

Using the monomer (a4-1-7), dioxane in an amount equal to 1.5 mass times the total amount of the monomer is added to obtain a solution. To the solution, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) as initiators were added in 0.7 mol% and 2.1 mol%, respectively, based on the total amount of monomers, and the resulting mixture was heated at 70°C. It was heated for about 5 hours. Then, the obtained reaction mixture is poured into the liquid mixture of a large amount of methanol and water, and resin is precipitated. The obtained resin is filtered. The resin thus obtained is dissolved in other dioxane to obtain a solution, and the solution is poured into a mixture of methanol and water to precipitate the resin. The obtained resin is filtered. This operation was repeated three times to obtain a copolymer having a weight average molecular weight of about 18000 in a yield of 77%. The said resin which has a structural unit of the following formula is called resin X1.

Synthesis Example 7: Synthesis of Resin X2

The monomer (a5-1-1) and the monomer (a4-0-12) are mixed with each other so that the molar ratio of the monomer (a5-1-1) and the monomer (a4-0-12)) = 50:50, Methyl isobutyl ketone in an amount equal to 0.6 mass times the amount of the monomer is added to obtain a solution. To this solution, azobis(2,4-dimethylvaleronitrile) as an initiator was added in an amount of 3 mol% based on the total amount of the monomer, and the resulting mixture was heated at 75 DEG C for about 5 hours. Thereafter, the resulting reaction mixture is a mixture of a large amount of methanol and water to precipitate a resin. The obtained resin is filtered to obtain a copolymer having a weight average molecular weight of about 15000 in a yield of 88%. The said resin which has the structural unit of the following formula is called resin X2.

<Preparation of resist composition>

A resist composition was prepared by mixing and dissolving each component shown in Table 1, followed by filtration through a fluororesin filter having a pore diameter of 0.2 mu m.

< Resin >

Resin: A1 to A2, X1 to X1 prepared by synthesis of resin

< Salt (a) >

I-1:

I-2:

I-3:

I-4:

I-5:

I-6:

I-7:

I-8:

<Acid generator (B)>

IX-1: the following salt synthesized according to the method described in Examples of Japanese Patent Laid-Open No. 2011-37837

B1-5: salt represented by formula (B1-5)

B1-21: salt represented by formula (B1-21)

B1-22: salt represented by formula (B1-22)

< Weak acid intramolecular salt (D) >

D1: The following salt manufactured by Tokyo Kasei Industrial Co., Ltd.

< Solvent of resist composition >

265 parts of propylene glycol monomethyl ether acetate

Propylene glycol monomethyl ether 20 parts

2-heptanone 20 parts

γ-butyrolactone 3.5 parts

<Production of negative resist pattern>

On a 12-inch silicon wafer, an organic anti-reflection film composition ("ARC-29", manufactured by Nissan Chemical Co., Ltd.) is coated and baked at 205°C for 60 seconds to form an organic anti-reflection film with a thickness of 78 nm do.

Then, one of the resist compositions is applied by spin coating in such a way that the film thickness after drying (pre-baking) is 100 nm.

Thereafter, the obtained wafer was prebaked on a direct hot plate at the temperature given in the "PB" column of Table 1 for 60 seconds.

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The resist layer formed on the wafer and the layer were subjected to a trench pattern using an ArF excimer laser stepper for immersion lithography (XT: 1900Gi; manufactured by ASML, NA = 1.35, Annular σ _out = 0.85 σ _in = 0.65 XY-pol.) Using a mask for forming (pitch 120 nm/trench width 40 nm), exposure was carried out by changing the exposure amount stepwise. Ultrapure water is used as the immersion medium.

After exposure, a post-exposure bake is performed for 60 seconds at the temperature given in the "PEB" column of Table 1.

Then, using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.), development was carried out by a dynamic dispensing method at 23 DEG C for 20 seconds to prepare a negative resist pattern.

The effective sensitivity is expressed by the exposure amount at which a resist pattern having a trench width of 40 nm is obtained.

< Line Edge Roughness Evaluation (LER) >

The unevenness of each wall surface of the obtained resist pattern was observed with a scanning electron microscope.

The mark "○" is given when the width of the unevenness is 4 nm or less.

The mark "x" is given when the width of the unevenness exceeds 4 nm.

Table 2 shows the results. The number in parentheses means the value of the width (nm) of the unevenness.

The salt (a) can provide a resist layer with low line edge roughness (LER), and can be used in a resist composition useful for microfabrication of semiconductors.

Claims (11)

A salt having an anion represented by formula (a2).

[Here, X ^a and X ^b each independently represent an oxygen atom or a sulfur atom,
X ¹ represents a divalent group having an alicyclic hydrocarbon group, the methylene group contained in the divalent group having an alicyclic hydrocarbon group may be substituted with an oxygen atom or a carbonyl group, hydrogen contained in the divalent group having the alicyclic hydrocarbon group The atom may be substituted with a hydroxyl group or a fluorine atom,
Ring W represents a C ₃ to C ₃₆ alicyclic hydrocarbon group, the methylene group contained in the alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxyl group, a C ₁ to C ₁₂ alkyl group, a C ₁ to C ₁₂ alkoxy group, a C ₃ to C ₁₂ alicyclic hydrocarbon group, a C ₆ to C ₁₀ aromatic hydrocarbon group, or a combination thereof. ,
L ^b1 represents a C ₁ to C ₂₄ divalent saturated hydrocarbon group, the methylene group included in the saturated hydrocarbon group may be substituted with an oxygen atom or a carbonyl group, and a hydrogen atom included in the saturated hydrocarbon group is a fluorine atom or a hydroxy group may be substituted, and
Q ¹ and Q ² each independently represent a fluorine atom or a C ₁ to C ₆ perfluoroalkyl group.] The method of claim 1,
A salt wherein the alicyclic hydrocarbon group is an adamantyl group, the methylene group contained in the adamantyl group may be substituted with an oxygen atom or a carbonyl group, and the hydrogen atom contained in the adamantyl group may be substituted with a hydroxyl group. The method of claim 1,
The salt whose ring W is a ring represented by a formula (a1-1), a formula (a1-2), or a formula (a1-3).

[In each of the formulas (a1-1), (a1-2) and (a1-3), the methylene group may be substituted with an oxygen atom, a sulfur atom, a carbonyl group or a sulfonyl group, and the hydrogen atom is a hydroxyl group; It may be substituted with a C ₁ to C ₁₂ alkyl group, a C ₁ to C ₁₂ alkoxy group, a C ₃ to C ₁₂ alicyclic hydrocarbon group or a C ₆ to C ₁₀ aromatic hydrocarbon group.] The method of claim 1,
L ^b1 is *-CO-O-(CH ₂ ) _t -,
t represents an integer from 0 to 6, and
* is a salt representing a bond with -C(Q ¹ )(Q ² )-. The method of claim 1,
A salt in which X ¹ is a divalent group represented by the formula (X ^1-1 ), the formula (X ^1-2 ), the formula (X ^1-3 ), or the formula (X ^1-4 ).

[Here, R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a C ₅ to C ₁₂ alicyclic hydrocarbon group, and the methylene group included in the alicyclic hydrocarbon group is an oxygen atom or may be substituted with a carbonyl group, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a hydroxyl group or a fluorine atom,
* indicates a bond with X ^a and X ^b .] An acid generator comprising the salt according to claim 1 . A resist composition comprising the acid generator according to claim 6 and a resin having an acid labile group. 8. The method of claim 7,
A resist composition further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. A method for producing a resist pattern comprising steps (1) to (5):
(1) a step of applying the resist composition according to claim 7 on a substrate;
(2) drying the applied composition to form a composition layer;
(3) a step of exposing the composition layer;
(4) heating the exposed composition layer; and
(5) A step of developing the heated composition layer. delete delete